I own a 2014 MBPr with the Nvidia chip and I'm thinking the AMD chip would be a big improvement. I see major visual artifacts whenever the GPU switches, it locks up frequently, and external monitors rarely work. Maybe a bad chip, actually, but it works fine in Windows.

There's an extended warranty repair program for video issues https://www.apple.com/support/macbookpro-videoissues/

Unfortunately, even though my MBPr exhibits exactly those issues, it is a Late 2013 model so it doesn't qualify.

I've had the same experience on desktop & mobile. The desktop issues with Radeon are from quite some time ago, but the driver problems on both Windows & Linux back then were extremely frustrating: random framerate slowdowns, no working linux drivers, bad support in some games, ...

And the only time a Laptop has died on me was when its AMD GPU decided to go crazy, resulting in artifacts and full system shutdown within a few seconds/minutes, if you were lucky enough to get it booting at all.

I know that this is anecdotal and most likely just coincidence, but I haven't had such problems with nvidia, so that I'm willing to pay the small premium price whenever I need a new GPU.

I'm not sure how relevant Windows / Linux experience is. Apple is responsible for the graphics driver on OSX. AMD may write much of the code, but it doesn't go out the door until Apple is happy with it.

AMD user. Not my experience.

How long ago was it?

Well over a dozen times from ~1998--2010.

I haven't had any real issues with AMD, so take it nots universal. Especially on my mac, the windows ones have been fine as well, but a little less stable since those drivers are more cutting edge.