I have been wondering the same thing regarding PP. I am a mac user and an AP2 user. I have been thinking about upgrading to AP3, especially since it's ~80$. But, I saw Amazon selling the LR3 regular (non student/teacher) copy for 150$. It made me wonder if it is worth jumping ship.
I'm just an enthusiast so not a whole lot of demands. I wish the AP2 had better printing options, curves, lens correction, split-toning, the presets that I see LR3 users have, and maybe layers- type feature. (I fully admit that some may already exist with AP2 that I have overlooked.) Which if any are in AP3. By better printing options, I mean it would be nice to simply choose say 2 different photos that I can print out on a single sheet of photo paper.
If I understand what folks are saying here, I would have to upgrade to 8 gb RAM regardless of application which adds 50-75$ to my purchase. I also assume that much of what I have learned and use with AP2 would carry over with AP3, as opposed to learning a new interface. So, I guess I am leaning AP3. But, I have the impression that there is more LR3 users, features and support. (Maybe I am too much a Scott Kelby fanboy
I do like his books and he has so many good tips for part-time hacks like myself.)
Anywho, thoughts and words of wisdom appreciated in advance.