Both are good guns. The mini 14 is much cheaper than most ARs, so it's hard to compare them. That said, I'll take a quality AR every single time.
ARs not reliable? When, in the late 1960's? My ARs have been perfect. They shoot everything I feed them, even cheap Ruskie ammo. As long as you clean them (I waited 1000 rounds at most), they are very reliable.