I've heard more people argue against it's use than for it to be honest.
It's not very hygenic, hard to spot clean. When you do clean it, you have to remove it from the viv, give it a good clean and wait for it to dry. Which means you really need 2 pieces of astroturf, one being cleaned and one for the viv.
The other problem seems to be that it's not much use for snakes to burrow in, which corns love to do.
I'm sure there are plenty of people with a different view but for what it's worth, that's mine.