Soccer (aka Football everywhere beyond North America) is starting to adopt artificial turf. I first played ultimate on turf regularly my first winter in Montreal on the new version--field turf. For me, the biggest downside is that my shoes, my car, my bag and my house now get lots of little black pellets from the field. In these kinds of fields, old tires are shredded and the result is spread across the field to simulate dirt, I guess. I dive all the time, and don't get too scraped up. However, that might just because I now wear various forms of UnderArmour to protect my hips (used to get nasty scrapes on grass or turn when I dive) and elbows (I have scars from the years of hitting the same spots again and again) rather than the improvement in turf.
I do think my ankles ache more after a night on field turf, but I know my knees and ankles are better off on a flat surface than the bumpy/hole-y grass fields we play on. I guess I don't want to see natural grass go away, but I don't mind playing on good fake turf either. And for winters, there is no substitute.