I've owned five Bushmasters and still own four. Never looked any further. All mil-spec and none have ever been picky.
Actually much of the Bushmaster is comspec... Important parts such as barrel, BCG, receiver extension and sight height. At about the same price point PSA and Spikes sell a milspec AR (except of course for the auto fire control group). BCM, Daniel Defense and Colt do too, but for a little more money.
Bushmaster may have been better in the past and if you have one that's working out, that's fine ... but if buying today there ARE reasons to look further.