Hi guys: We develop software and need a system that can still run OS X versions going back to Mountain Lion natively. Right now I'm looking at used late 2012 Mac Mini's and used late 2012 21.5" iMacs. Oddly, or so it seems to me, the iMac's comparably configured are selling for about the same prices as Mac Mini's. I realize that because Apple has castrated the newest Mac Mini's (worse performance than the 2012 models, soldered in RAM, generally non-configurable, etc. etc) may make the 2012 units command a price premium, but honestly, some of the prices they're selling for used are ridiculous. I would prefer a Mac Mini, but for the same price, why not an iMac. The fact that the iMac sold for so much more than a Mac Mini has me worried that there's some type of known issue with the late 2012 iMacs. Are these units to be avoided for some reason? Thanks.