I have one. It is loud and slow. I found the resulting food products to be at best serviceable. Unless you have a specific purpose in mind or buy a very large amount of freeze dried goods then I would skip it. Mine sits right next to the electric guitar, I didn't learn how to play, in my collection of unused and expensive things. I am happy to sell you mine, but I can't recommend it.
If you are bored, have some extra cash and want a new toy check out a pacojet. About the same price, but your friends and family will love the ice cream.
Sorry, for the corny humor, but I hope this helps.