Only real downside that I have observed with these is separation of the bolt handle from the bolt. The newer version with slightly rear swept handle is better than the earlier version with the straight handle. Have personally observed at least 18 of these with the handles off. These rifles had been subject to hard use, plus abuse. No one here is going to hit the handle with something because a case is sticking in a pitted chamber.
As mentionned above, bolt stops break, as do the plastic tops on the safeties, and the plastic finger piece on the mag. catch. Parts availability is catch as catch can.