They weren't too awful to work on, but they did require a lot of work to keep running right (I worked in my company arms room for awhile). I wasn't really a fan, but they aren't as bad as I remembered, either. They'd work the rivets loose in the receiver without a lot of effort, though. We used ours pretty hard (lots of training time in the 82nd Abn).

You can roll a turd in peanuts, dip it in chocolate, and it still ain't no damn Baby Ruth.