[shimms]

Yep - they're great.

I've put in USB3, replaced the spinning disk with SSD, upgraded the WiFi and RAM, but haven't done the CPUs yet (already got dual 6 cores, so aside from a slight clock bump not much point).

My only concern is that the CPUs don't support something that the next major version will require, forcing a move off the MacPro 5,2 platform.

[jsjohnst]

I also did USB3, upgraded wifi, SSD (also turned it into a custom fusion disk), ram bumped to 128gb, upgraded from dual quad 2.4ghz to dual hexacore 3.3ghz, added a nVidia 1080Ti (which I had to power off an extra SATA connector from the 5.25” drive bays) and upgraded the ATI (kept it split brands as the nVidia can be a momentary pain when doing OS upgrades).

I also share your concern too. :(