GETSOMESAUCE  PDFpenPro is a powerhouse of thought and action, but its inclusion into your workflow may prove to be a frustrating experience.

For the money, PDFpenPro (and PDFpen) offers tremendous value compared to other paid offerings such as Acrobat, PDFClerk, and PDF Studio while offering tremendous abilities over the free alternatives such as Apple's Preview or Skim.

Pros and Exciting Nuances:

1) The addition of an OCR engine to the program is a powerful move by SmileOnMyMac. No other program aside from Acrobat has even ventured into this realm.

2) It's applescriptable.

3) Little things - This is the only PDF program I've found that correctly selects/highlights PDF text when the page has multiple columns.

4) It has the ability to edit text that is already in the PDF as well as draw in your own text boxes to add text of your own.

5) It's a Universal binary.

6) Incredible tech support. So incredible, it's practically emotional.

7) Library Pallet - Collection of commonly used shapes and signatures.

8) Primitive layer control. That's a good thing.

9) It has the ability to make an integrated image transparent. Totally genius.

10) Very nicely prepared and thorough help system.

While wrought with exciting capabilities, Apple's bomb.app (Remember? From 10.0? Google it.) is occasionally more productive. You'll need to exercise patience save often.

Cons and Annoyances:

1) It's buggy. It's Buggy McBugbug. It's bugtastic. It's Bugfest 2008. The bugs are manageable and you'll come up with workarounds, but they're there and numerous.

2) No ability to scroll from one page to the next. You can scroll through a single page, or scroll through the thumbnails, but no scrolling through an entire multi-page document using the scrollwheel or slider.

3) Can't scale the document size.

4) No ability to crop an image. (Yes, there's a menu option called "Crop Image", but it just scales an image without letting you crop it...and yes, you can crop an entire page, but not a separate integrated image.)

5) Can't zoom by creating a zoom window. KnowwhatImean? Sure, You can hit the "+" or "-" buttons to zoom in or out, scroll around the document, then hit those buttons again, but wouldn't it be nice to be able to select a portion of your PDF and have it zoom right in/out for you?

6) Very, very, very limited ability to handle PDF permissions.

7) Very limited control over printing options. Want to scale an image to fit the entire page when printing? You can't. Want to print non-contiguous pages from your PDF (in one step)? You can't. Sadness reigns.

8) The OCR engine WILL crash on you. The longer the document, the higher the chances.

9) It's slow. Sluggish, like a wet sponge. It's Sloe McSlow. It appears to only be able to use one processor, and suffers for that.

10) No way to turn off those pesky page numbers that appear at the bottom right of every document.

On the whole, I love this program. It's chock full of such sweet milk and honey that it makes me happy to be alive. However, you'll only keep your sanity when using PDFpenPro if your PDF workflow includes a stable companion such as Preview or Skim. I think it offers a good value for it's cost and features, but that's just my vote. By the way, if you want PDFpenPro, go to their website and start to purchase PDFpen (non-Pro) and it'll offer to sell you (also known as "upselling") PDFpenPro for $90...which is $10 off. Happy PDFing.  
(Version 4.0.1)

NBREGI [PT]  If you just need to write on a pdf use FormulatePro, It's FREE and simple.  
(Version 4.0.1)

UMIJIN  Warning to PDF Pen/Pro users of v3.5 and earlier:

This is a PAID upgrade if you purchased either product before June 08.

I hope the developers will insert a statement in their MU product description to avoid any confusion.  
(Version 4.0)

CHIEFTED  Making a change to a pdf file has never been easier. I have been using PDFPen Pro for a couple of years now and it has never let me down.

Currently I need to make annotations to about 75 pdf type files a month and this program makes it a snap.

Its simple, fast, cheap and best of all, easy.  
(Version 3.4.1)

HEROLINT  PDFPenPro does some nice things, but there are too many deal breakers.

First, when you try to center text in a text field, the size of the text field will grow to the length of a football field. There is a work around for this, but it shouldn't happen in the first place.

Second, the grid doesn't work right. If you place an object on the screen when the snap-to-grid feature is turned on, it lines up right, but if you lay something out without snap-to-grid, and then turn the grid on, instead of aligning the corner of the object and the corner of the grid, it will align to wherever the grid intersected the object when you turned snap-to-grid on. The only way to fix this is to delete the object and recreate it.

Third, the snap-to-grid functionality is not granular enough, making complex page layouts a huge pain in the butt.

There are some other issues too, but these were the main ones.

I like one of the company's other products quite a bit, Text Expander, but I do not recommend this one unless you are planning to do some extremely basic documents with it that contain editable fields. Otherwise, just print to PDF. It's cheaper.  
(Version 3.4)

STUDY  worth the money!  
(Version 3.0.2)

ANONYMOUS  I am wondering if there is anything else that are similar in funtion to PDFpenPro 2.0.1, but costs less? ($95 is still a lot of money to me) ;)

Any tip would be appreciated!  
(Version 2.0.1)

WHYTOI  What's the differentiation of this with Adobe Acrobat Pro and Reader?  
(Version 2.0)