I've been having one for about a year & a half without a single failure. They do give recommendation on ammo type to use & I haven't used anything but what is recommended. The only problem I have with mine is finding enough 22 mag to keep up with my habit.
After their 1st production run they changed the twist rate because of some issues with key holing. When they changed the rifling they changed the barrel from a fluted to a smooth barrel. So, if you find one, just make sure it's the smooth barrel & you shouldn't have any issues.