Just tried one in Arizona. Very fun toy, but it is a toy and you will become bored with it quickly. Ammo is so ridiculously expensive now, it is not a very accurate way of shooting. Best advice in this thread is go to a range that rents full auto, try it and then picture how much ammo you would burn if you owned one.
It was super easy for me to talk myself out of it (besides they are illegal in my state). If you are made of money and keep 5k to 10k rounds of ammo on hand, lot of fun, but expensive fun and not really fun with a point, it isn't teaching you anything if you ever want to shoot subgun matches or something like that.
I admire the innovation but FA is a one-trick pony for most. The idea of owning one is more fun than the reality of owning one. Now suppressors and SBRs, a lot more practical to actually own and buy.