YMMV! As an non-power, graphics-wise, Linux user (that is, no 3d), my experience has been better with AMD than Nvidia (owned multiple Nvidia cards and a modern AMD one).
In daily usage, I think I've found one issue with the AMD card, and a couple with the Nvidia card. What's worrying is that when filing bugs while using an Nvidia card, devs both times gave the pseudo-automated answer "we can't solve that, Nvidia drivers are closed source", which was wrong in one case.
In Windows, I've used all the cards for gaming only, and never had any issues.
Agreed that YMMV, I have heard about these issues in that reddit thread about NVIDIA cards as well and have experienced the hardware acceleration bug for example.
In daily usage, I think I've found one issue with the AMD card, and a couple with the Nvidia card. What's worrying is that when filing bugs while using an Nvidia card, devs both times gave the pseudo-automated answer "we can't solve that, Nvidia drivers are closed source", which was wrong in one case.
In Windows, I've used all the cards for gaming only, and never had any issues.