You're absolutely right. I didn't provide all that information as I don't generally try and write a novella. As I said before, for a light duty carbine, home defense, light personal use, it will likely run just fine. Your Bushmaster runs great. Thats awesome. As I said before, they will likely work for the original poster too. The question was asked why are they not considered a topflight manufacturer. I responded with mostly accurate information. I readily acknowledge where I was in error. Shot peened bolts, properly staked gas keys, MPI bolts, Pressure tested bolts... are the halmarks of top flight manufacturers. Bushmaster does not do that. If you don't think they're needed, that is fine. Its your rifle. Passing on those tests/features makes them "less then" in my opinion and in the opinions of people who will forget more about ARs then I'll ever know.
The courses we teach are patrol rifle courses in Yakima Washington. The Federal training center and private ranges are covered in a very fine volcanic ash. The environment eats gear. The only thing that runs without fail are Aks. Ars quit, Glocks quit, FALs (near and dear to my heart) quite. Springfield XDs quit. We run a hot range and work the gear hard. I mean smoking hot hanguards, burnt hands, smoke billowing out of over oiled AK wood. Cuts and bruises. Again most people won't run an AR that hard. Most people won't shoot in a year what we will shoot in a day (halfway through the first day we do a 90 round drill that takes a couple of minutes). The ARs that run best, in my experience are Colts, and other mil spec guns. Bushmasters tend to fair less well. I'd say i've seen dozens of rifles in these courses and I get a sense of what works and what doesn't. I will say that the key to keeping an AR running is to 1) keep a magazine in it at all times and 2) keep the action cover closed at all times that you are not shooting. I use an AK most of the time, so I don't have those issues.