My two cents worth:
These rifles are similar but not identical. They shoot similar rounds, mini's are marked .223 and AR's are marked 5.56. Supposedly these are different cartridges. They are similar but different.
Both use hi cap mags-most mini mags are steel, steel is better than aluminum which is used in 'most' AR mags.
The AR's biggest problems is the tight clearances in the bolt/chamber lock up. Tight means better....sometimes. The mini is not as tight or picky in this area, this is better....sometimes. If you go back and dig out some old info about the problems in Nam w/AR, most of the problems point to powder. What I have read is that the powder used at first was old. It had been stored with calcium carbonate to absorb any moisture, calcium carbonate is "dirt" when mixed with powder and fired==>JAMS!
The mini is cheaper when new (used the price is very close in this area) than the AR. The AR has better inherent accuracy. Spend the money to equalize price and the mini shoots as well.
Repair parts are easier to find for the AR than the mini.
The AR is black and scary-my mini's are all black and scare my Beamation (half beagle and half dalmation), the German Shepard doesn't care. I take the wood off and go to synthetic on my mini's because synthetic's hold up better. If I want people to like my guns I'll carry a lever action, all
non-believers think you are Roy Rogers or Gene Autry then.
I like the collapsible stock better than a folder because I shoot long guns left handed. Shoot handguns right handed. My DI loved that, and oh yeah, I qualified expert and he was a sharpshooter. I have one BC folder w/AR collapsible stock and am going to convert one or two more for some of the mini's.
What do I have, six Mini 14's, one Mini 30 and four AR 15's-two 20" and two 16" What do I want if the feces contacts the westinghouse, for the non PC, that is when the SHTF. Any one of them will do, along with 10-15 mags and all of the ammo I can hump. Second choice would be a Ruger 10/22M or Marlin 922, You can carry a lot more 22 mag ammo than 223.
This brings up a question that I've wondered about since finding this web site, why do most of us have mini's or AR's-->when the SHTF or plinking. A 22 makes a better plinker so I guess that means for when the SHTF.