A lot of times Minis aren't being compared to one gun but a variety of ARs and for different reasons. Also on the internet being a little worse at something is almost as bad as being a huge pile of duke to begin with. So it won't be as accurate as a guys White Oaks upper, won't be as cheap as another persons PSA kit gun and won't be the modular platform of the guy with 4-5 different uppers. Sometimes though it seems like the guy with the 4moa red dot on his M4gery (shooting surplus M855) will be complaining about the lack of accuracy of a Mini compared to the match grade upper he doesn't even own.
I think Minis are great and mine has been far more reliable than the M16a2 and M4 I deployed with. Mags the pivot in take longer to reload than a mag that gravity will pull to the ground but it isn't like the Mini mags are one of a kind. I don't ever hear people saying they bought an AR10 over a M1A because of how you insert the magazine into the gun.
New gun, same ol' shot.