One thing I found while switching from an iPhone 3G to the Atrix was that the screen became SO much more responsive. This is my first Android phone, so I really have nothing else to compare it to (aside from my 3G), but I find the screen itself to be extremely responsive. After putting the screen protector that came with my Commuter on, I still find the screen's responsiveness to be amazing--far better than my old iPhone 3G. Now, I don't know if it's just my imagination or not, but I would like to believe that I do notice a slight decrease in sensitivity. Either way, I still find the Atrix's responsiveness to be amazing. Even with the screen protector on, I can literally hover my finger
just above the screen and it will still register.
Now, I have noticed that the space bar seems to be the least responsive part of the screen while typing. It too may have gotten slightly worse with the screen protector, but I noticed issues with it beforehand. (Anyone else have this problem?)
As I haven't hit the magic number yet to properly insert links/images (the recent Atrix launch brought me here), below are the direct links to some pictures I snapped this morning with the case on. Sorry that they're not the greatest! You can clearly see the lint-magnet properties in action too

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http://i19.photobucket.com/albums/b178/davethemage/Public/IMG_0128Large.jpg (front)
http://i19.photobucket.com/albums/b178/davethemage/Public/IMG_0119Large.jpg (back)
http://i19.photobucket.com/albums/b178/davethemage/Public/IMG_0121Large.jpg (lock button/top)
http://i19.photobucket.com/albums/b178/davethemage/Public/IMG_0131Large.jpg (side angle)
http://i19.photobucket.com/albums/b178/davethemage/Public/IMG_0125Large.jpg (side angle)
http://i19.photobucket.com/albums/b178/davethemage/Public/IMG_0122Large.jpg (volume buttons)
http://i19.photobucket.com/albums/b178/davethemage/Public/IMG_0123Large.jpg (USB/HDMI)
The volume buttons are securely inside of the cover, whereas the USB/HDMI can (obviously) be opened to allow access to the ports. There is also a cover located over the headphone jack. The USB/HDMI covers don't fit as snugly as the cover over the headphone jack.