I just picked up the MOE M&P AR-22/15 and it has those "new" Magpul sights on it. I'll admit, when I saw them coming to the market, I was excited; I'd never seen a pair in person until I got this rifle the other day. While they seem somewhat secure and sturdy, I do see them being more fragile than traditional metal sights. Granted, of course metal is more sturdy, but I guess what I'm getting at here is -- are there any KNOWN PROBLEMS with these sights? The sight post on the front sight just seems like its dying to snap right off is something were to get inbetween the winged guards... So -- what say ye? Good/bad or decent for $100 for a pair of flip-up sights?