DOM21  Performs flawlessly for me on an Intel 24" iMac, OSX 4.11.  
(Version 1.67)

PIXELJUNKEY  Nice product but BIG system resource hog... on dual core Macbook pros, a 24 fps capture with audio uses over 100% CPU and causes the fans to spin up constantly.  
(Version 1.66)

XPLICIT  Every 2 to 3 days a new update, what's that all about?   
(Version 1.64)

NICKEL  iShowU is an excellent application. It's great for recording anything on your screen easily and efficiently.  
(Version 1.62)

LAINSNAVI  Garbled video in 1.61! Yargh, back to 1.6. I'd make more of a fuss, but anything after 1.55 is a test version.

Mac OS X 10.5.2

Intel Mac mini

1.66GHz Core Duo

2GB DDR2 SDRAM

GMA 950 with 64MB of shared memory  
(Version 1.61)

IAMDORIAN  More capture .. for the buck. Although things like the marquee are not as slick as it's chief competitors', this is a great app for a good price. Way to go!  
(Version 1.58)

GAMER9ER   Fixes

o Fixed a memory leak that could cause a crash after 10+ hours of recording.

o Fixed incorrect audio (left/right) balance when "Record system audio" is enabled.

Changes

o Reworked all presets. Most now use Apple Animation (generally better for performance), added a preset for WoW that uses Apple Intermediate (if available) or Apple Animation with a slightly reduced frame rate if AIC isn't present. Presets are now included for iMovie HD, iMovie and YouTube / Blip.TV. If the FCP uncompressed codecs are present, then presets are created for these as well. Note: The new presets will only appear for new users. If you want you can reset your existing presets (see the Edit menu), but this will erase your existing presets.

o Sorting for descriptors is now case insensitive (generally makes more sense).

o Default microphone and system audio volumes are now 100%.  
(Version 1.55)

JRWHO  After a lot of testing around with this app, I love it! It does need a couple more features, but v2 is coming up.  
(Version 1.54)

LEIFH  I'm trying to record my keynote because the built-in recording feature doesn't record my transitions but this uses 150% CPU according to activity monitor, and that's on Intermediate Codec (supposedly the least CPU intensive). I've tried everything else on the list and they all run at over 100% so my keynote lags. I'm using an intel imac (1.83 ghz) btw.  
(Version 1.54)

DOM21  Nice, but confusing... what are you supposed to Press when you want to keep a resized screen? The symbol it tells you to Press doesn't correspond to anything on a Mac keyboard!  
(Version 1.53)