I'm a happy PRS-700 owner.
I roughly estimate I've spent around five hours reading with it so far and I'm very pleased. Typically I swipe my fingernail to turn pages so that I don't leave smudges on the screen - when I use my fingertip it can leave marks due to oil on the skin. I'm not using the stylus for the most part. Glare has not been a significant factor, although I have noticed it from time to time.
I have also read for some time in the dark using the sidelight, which works very well. You certainly notice the light but it's still easier on my eyes than a LCD backlight.
I believe that if you are used to the PRS-500 or PRS-505 screen that the PRS-700 screen is a step backwards. However, in no way was the PRS-700 a step backwards for me, personally, as my previous reader is a Sony PSP using bookr. The integrated light and touchscreen are important features to me. Now the only thing missing is wireless!