I didn't like the form factor of the Charge either. I did love teh screen however.
In regards to the lagginess I came across, the screen was generally responsive, but on occasion, pressing an icon to launch a program was sometimes a bit of hit and miss. Sometimes it launched immediately, and some times it took more than one press, or a long press. This is something I have not seen on other phones (TB, and Charge). Could've been the unit in the store so I'm going to check out another store's to see if it is endemic to the phone or not.
As for the pictures, the Charge to me had the best images. Best color, definitely least JPG compression, largest file size, best grain, Less aliasing, etc...
Thunderbolt had most compression and ailiasing, but the colors were nice.
The Revolution has about the same level of detail as the Charge, but colors did not seem as spot on as the other two. Also has way less compression artifacts than the TB. Again kind of a cross of the other two.
The images from all three are attached. the Charge is 100% crop since the whole file is too large for the forum. The other images are full size and no processing has been done to them. They are as they came out of the phone's camera.