Screen protectors.. is there really a difference?

"Screen Only" Typically means the entire front of the phone with most good screen protectors. A "Full Body" one has a piece for the back, along with the sides and top/bottom of the phone.
 
Also, to brandonc, how did u turn the ambient sensor back on? Do u mean auto brightness?

Sorry I didn't answer this earlier- yes the auto brightness feature. Most phones I hate it- but on Evo I feel it works pretty well and the shift from different levels is very gradually done so you don't notice it dimming.

Like it a lot and I do feel it helps reduce eyestrain.