Mini-Cheaper to buy, less intimidating to non-warriors. New ones are fairly accurate, older S/N mini's are about as accurate as a shotgun. Parts/accessories somewhat limited. If you are going to buy a Mini-14, be sure it is after the S/N break(I think about 2005 yr.).

AR-More money, vast selection of parts/accessories available, potentially more accurate if you choose those parts wisely. Has military "Black gun" look that gets anti's undies in a bunch.