I've been using Aperture since January, and have also tried Adobe's Lightroom. Both products are works in progress, and will get better with revisions. Neither is clearly superior to the other, and both have strengths and weaknesses.

Despite all the complaints in other reviews on VersionTracker, I find both of them great first generation products -- clearly on par with other Apple products when they were first released (iPhoto, iTunes, iMove, iDVD, etc.). All of those products improved greatly with each revision, and I see no reason why Aperture won't also. I encourage you to try both out and come to your own conclusion. But don't bother with Aperture unless you have a very fast Mac -- I have a G5 dual 2 GHz (before they upgraded the video card), and Aperture strains the system -- particularly doing things like straightening photos. Version 1.1 is a bit faster, but still marginal in the speed category.

Apple has shut down its Aperture development team and will either pull the plug or more likely staff it with a new team from the professional video part of Apple. I hope it is the latter, since the program has great potential.

FYI, I was disappointed when I upgraded in February 2006 to a Nikon D200 and found out Aperture could not read the RAW files (while Photoshop, iView MediaPro, Nikon Capture were all fine), but this has been fixed with version 1.1 of Aperture.