JUSTIN BRACKEN  I really wanted a piece of software to properly label the songs I had ripped awhile ago. My first mp3 players did not read the meta tags so when I ripped them there was not much point to label the song more than a quick label on the folder the file was in. Now with itunes and the iphone having album art and proper meta tags makes a big difference.

I tried tuneup, song genie, and song sergeant. Song sergeant from what I can tell does not do anything with identifying a song from acoustic fingerprint or acoustic id. tuneup and song genie look like good programs except they are ~$10 more per license.

As far as licensing jaikoz goes it was a snap. Even when you include the fact that I had a paypal account but had never used it purchasing anything in the mix licensing the software was a simple and quick. Yeah for instant gratification. You don't need to license it as the software will do 20 corrections per launch so going beyond that requires only a restart of the software but for $25 or what ever it cost the software is well worth the price. Heck breakfast was more than this, this morning! Plus this includes all updates if I remember correctly so thats a plus I do not think the others included that.

As far as features go this program has more than you probably know about, need, or want to use. It has automagic mode for those less picky about their audio collection and just want a proper label put on them with album art. To detailed mode where you can mess with the algorithms parameters used to choose the id3 tag. You can set it so that it chooses id3 tags which result in fewer separate albums. For instance if you have a song that was released on multiple albums like a hit album and the original album and also have other songs that are in a similar situation it can be set to tag the songs such that they are from the hit album so instead of 10 songs on 10 albums you have 10 songs on one album. It will even tell you what songs you are missing from the album. It does the duplicate search thing to althought I haven't messed with that.

The software was simple to use. Just add files from your disk and then tell it to automatically scan and correct. However the ui is not what I expect on a mac. Not to say that its bad but a user who is used to mainstream software will find it slightly less usable until they use it and get used to it. I think you will like the choices made once you are use to it. The user manual: http://www.jthink.net/jaikoz/jsp/help/osx/frames.html is great except the author either has english as second language or used a software translator so there are some word order problems.

As far as value, its cheaper than the competition I looked at, arguably has more features, and includes all updates. Plus free support by email. Enough said!

Stability, has not crashed yet.

My recommendation, buy it or at least review the manual before you buy something else.  
(Version 3.3.4)

THUNDER82  Jaikoz is the best tag editor out there. I have tried many others including SongGenie/Coverscout, and Jaikoz is still the software that I find myself using the most. It has been 100% stable for me, even when i throw a few hundred songs at it. Those mentioning that SongGenie & Coverscout are better obviously don't need their software to do much. Sure these other programs have a nice interface (honestly, much nicer than Jaikoz) but their functionality is SO limited. Given the price tag (especially compared to the Equinux equivalents) Jaikoz is awesome.

The only improvements I'd like to see, would be a more "fluid" interface for OSX users and better handling of song lyrics. Pulling lyrics from the web is awesome, but I don't feel I'm able to properly manipulate the lyrics field. Being able to create paragraphs and separate the chorus from the rest of the song is important to me. Also, it would be amazing if there were an option to automatically delete the web link that gets added to the beginning of the lyrics added to each track.

Overall, Jaikoz is extremely feature rich and very stable. I'm very happy with my purchase.  
(Version 3.2.2)

SUNCHASER21  Great app, except that on leopard 10,5.8 it seems that when i add or drop 30 files plus, MP3 files on the desktop icon, it ALWAYS CRASHES.. every single time..

then one problem bigger when I am editing about 20 files in one window and I do search and replace the name.. for example. Mike, with the name MIKEY.. it will replace most of the text but everytime i try it, it will always miss 1 -4 songs and leave them blank.. Would love for the dev. TO try to help me with this problem. have emailed them 2 times with no answer.. Hum bad support. i SURE HOPE NOT.. i would love for this app to work great..

ANYONE LOOKING FOR SOMETHING DIFFERENT.. try ..COVERSCOUT.. and IGENIE.. the best. but cost $$ And i already paid of this. but be sure to check them out. they are great.. as in perfect.. hope this helps someone.  
(Version 3.2.2)

AIKOUSHA  Looks impressive. Unfortuately doesn't fit my needs. I need software that will properly fill Catalog Numbers (since ALL my music is from CDs I own, and need to reference if the track is used), as well as allowing at least two custom fields which are not represented in the massive collection of tags in the prefs.

And, why, on a Dual 2.5Ghz, does it take nearly a minute to start the program?  
(Version 3.2.1)

BLAINE J. MARSH  This is a terrific program - and the price! Originally, I was looking to get tag info from the filenames of about 700 flac files. What I found was a program that had features that I hadn't even considered. I was able to make short work of tagging hundreds of files that had only the song title in the filename. I was able get the song titles into the tags, easily add artist, album title, artwork, download lyrics, identify songs with Musicbrainz - all on a batch of files. Editing includes copy, paste, search and replace, strip wide spaces, strip spaces, correct spelling, capitalization - just way too many things to list. I suggest that you download a trial copy for free that allows tagging up to 20 files in one session. I used it once and was convinced that it was a bargain at 15 British Pounds.  
(Version 3.1)

WYNLYNDD  Jaikoz is an excellent id3 tagger and has helped me "save" my collection as poorly tagged songs made it difficult to find anything. The developer is rather responsive on his forums and often updates his wishlist and buglist to let you know where his priorities are at the moment.

In addition to cleaning up tags, it adds album art and lyrics, and can help dedupe your collection. Yes it can be a bit slow, but some of that slowness is the limitations of the MusicDNS servers that it uses to help identify songs. (they have a throttled limit of 1 song/second plus, the server is often busy causing Jaikoz to retry a few times to ensure it gets the information)

I concede that it can be difficult to load entire collections at once, especially as people's collections get so huge. (we are now what 11 years into the mp3 revolution?) However, it has improved and should keep improving (I can now get about 15K-20K loaded at once).

One of the best $22 I ever spent.  
(Version 3.0)

1CHARMEDLIFE  This is a great tool for managing large collections and their associated metadata. We have over 26,000 songs in our library and this did a great job allowing us to manage the tags.

The only drawback I've had with it is that it seems to embed multiple versions of album artwork with the files. It would also be really helpful to be able to tell the software to *not* fetch artwork under a certain size. (It stinks to have an awesome interface up on a big flat screen, and it's scaling 112x112 images up to fill a 50" screen... and weeding those all out by hand takes forever).

End to end though, this a great software and I highly recommend buying it if you have a large collection to manage.

(One other note, with really large collections, you have to process them in chunks unless you have tons of RAM. We have 4gb on the machine we used for this, and we could still only process around 10,000 songs in one batch... )  
(Version 2.8.1)

LIAM_IMAC  It works well at times but it is very slow app. it takes 30 secs or more to start and its not the most responsive app when running.  
(Version 2.8)

CFSCHOLL  The application works but you can't have your itunes open while changing your song information. I adjusted the tags of a song I was playing and itunes crashed. Afterwards it indicated that my files could not be found anymore so I had to find them in the itunes folder. The name of the artist had changed so I guess that is the reason why itunes thought they were deleted. The solution was easy I just added this folder again to the itunes and now they had the correct song information. As this is a 30$ application I would expect that the integration with itunes would be better. As for what others said about the speed its indeed not a problem.   
(Version 2.8)

THEBRIX2008  Having tried all the other (non-iTunes) taggers, Jaikoz wins. The only real downsides are the UI appearance - but that is a price worth paying for a cross-platform application - and some aspects of usability, as it is possible to cram up to four extremely "busy" panes (catalogue, tracks being viewed, tracks being edited, exhaustive details about the current track) into one window.

The most useful feature of all is that it is extremely easy to cut and paste information between tracks, as the track editing pane is spreadsheet-like. It is incredible that no other Mac application (that I have come across) has adopted this approach as it is by far the slickest when working with complex albums. The other big win is that, in effect, any field, including filenames, can be set automatically from the (parts of) any other field using macros: for quick cleanups (e.g. the common one I find where composer and artist are reversed) this approach is unbeatable. Finally, there is standards support for ID3 tags of every version; tags set in the iTunes view are automatically copied to the ID3 view so that any quirks, because of differences between the standards, can be ironed out on the spot. If you don't need it the ID3 view can be switched off.

And the MusicBrainz facilities work superbly; although I have less need of it than most (as I mainly listen to classical music) they fixed several "unknown" albums handily.

As others point out, this application is not meant for an existing, perfectly-tagged iTunes collection which will only ever be used on a Mac and an iPod; it is perfect for building a collection which is not tied to Apple products.  
(Version 2.8)