Very little difference, "carpet burns" will happen some because when all is said and done its a big carpet. There isn't very much adjusting to do because it feels like a very plush grass field. If there was much adjustment to be made installing it most likely wouldn't be a school option, either all schools would have it or none would because it would be an unnatural advantage. Quite a few HS around here have installed the surface. One of my best coaching friends is still AD at one who has and he said they saved a good bit of money from upkeep, but the biggest relief for him was making sure the field was painted for games, no more sweating blood trying to get a field painted during a week of almost constant rain and showers.
As for as playing faster, probably not much difference on these surfaces because of the base and it has basically a grass lenght knap to it. In the old days of astro turf being put over concrete with almost no padding, it probably played faster than natural grass, but those things were pretty rare and no HS had them when I was still coaching so thats a guess.