Honestly, the HK guns are quality weapons even if they are crazy expensive. There seems to be a preference for chrome lined barrels here in the US, but properly maintaining the weapon prevents rust. I like the Colt AR's best (personal thing, there are lots of AR's that are qualitatively better than mil-spec), but S&W doesn't produce crap. Is the Pro Tuning AR pretty close to mil-spec or better than mil-spec. They probably don't have the TDP that Colt and FNH USA have, but making quality AR's can't be rocket science with the number of US and foreign companies doing it. If an AR has the features you want, go for it. Quality is quality. Colt has the little pony next to the serial number and that's about as far as it being "better" than most other AR designs goes.