While the iPad1 is noticeably slower, I have found it running out of RAM around the same time as the iPad3 during app development. Oddly enough, the iPad2 really is the best iPad right now in terms of overall package performance. Of course the retina screen looks great, but the iPad3 hardware is just barely enough to support it. I'm expecting the iPad4 to really be the retina device to have.
>Oddly enough, the iPad2 really is the best iPad right now in terms of overall package performance.
I agree. For me it's the fact that the iPad2 stays cool after any period of usage. iPad3 has a noticable heat spot on the back and it really bothers me, it shouldn't, but it does.