I would go with the htc incredible 2 over the dx2 for the forward facing camera. The screen on the charge is nice.
Ohhhh, where to begin. Coming from a droid 3 to an iphone, I am disappointed with the iphone. If you are used to the droid interface and fratures, you will find the iphone to be very restricting. Also, the iphone 4 is behind the standard of hardware by a lot of todays standards(mainly the single core processor, i like retina display.) if i could do it all ove again, it would be the droid 3 i would have kept. The droid was faster, and (in my opinion) better in more ways than one.
I would go the iphone. I have bionic and love it, my wife has a X and loves it. The iphone hardware and software is really nice. There is something about the look of their OS that makes the screen seem bigger than it is. But apples hardware makes the X look like a plastic toy.