I play 4ed every Tuesday (in fact, I'll be playing in a few minutes). For what it's worth, I think the stable structure, simplicity and balance makes sure that allot more time is left for actual roleplaying. I played 3.0 and 3.5 longer than 4, but feel more at home with 4 already.

I feel making maps for 4ed, is somewhat... limited. It would work if it was a tile system or something that you can rearrange every other combat. In 4ed environment plays such a large roll that I tend to make a new combat map for every other encounter instead of reusing environments for several fights. So I usually just doodle lines on a white-board and be done with it. ><