Not OP, but just built at Ryzen 1600 box. I've had _more_ instability when running 17.04 and settled on 16.04 which has been mostly fine, but hard crashes occasionally.
This sounds disturbingly unacceptable yet accepted
Having experienced first hand AMD driver instability on both Windows & Linux, AMD have lost my custom for the next 10 years..
Multiple re-occurring driver crashes using their main graphics card product line(RX380) on Windows 10.. So, pretty mainstream and yet having driver crashing (even when doing non-intensive tasks e.g. web browsing)
For the record, I'm not so sure Nvidia is any more stable either. The only (constantly) stable graphics provider over the years has been Intel's on-board graphics.
I installed the official AMD RX580 drivers and it's been stable since.