I just built one, my first, last month. Works just fine, including sleep / wake and upgrading a minor OS release and installing apps from the App Store. I used

I just built one, my first, last month. Works just fine, including sleep / wake and upgrading a minor OS release and installing apps from the App Store. I used the TonyMac recommended set up, of which there are a ton of permutations, picking the i5 6600K CPU and a fairly middling ASUS Z170 motherboard. The onboard graphics is a huge step up from my mid-2011 i7 Mac Mini Server. Popped in a 960 gb SSD and it runs like a charm. I also have a MacBook Pro in hand in case things go really bad but so far no issues at all. (Except Messages, but I didn't use that on the Mac Mini so no loss there.) Can't recommend it enough. Great rig for about $600 including case and power supply, and when I'm ready to upgrade most of that investment will carry over (SSD, case, PSU, keyboard, monitor, etc). Far more sane and cost effective than the 5K iMac I was considering.