> is their driver remotely competitive in terms of actual usability/quality?

A resounding 'yes'. You must not be using their open source driver, or are using a very old one in your 'comparison' with nvidia's linux driver?

I tried it twice a few years ago. The first time I tried it it just had no support at all for the card (apparently too new); the second time it "worked" but felt pretty flaky, things like locking up much of the time if you tried to switch between X and console. Maybe it's better now - my experiences were bad enough that I swore off AMD for a while. (This was well after the point when their open-source drivers were established and people on HN were telling me they were good, though)

I have Vega 64 in my desktop, since the non-blower designs became available, and I had no problem with the amdgpu+mesa driver.

It is nice to have it work out of the box.

It is common knowledge that the AMD FOSS drivers nowadays work quite well. Spending a couple of minutes on Phoronix can verify that (they regularly report on such news). You even got multiple drivers to pick from (2 FOSS, 1 proprietary).

How much do you stress the GL implementation? See, I write rendering code fairly regularly and I need drivers that don't keel over in use cases that aren't covered by desktop compositing and the occasional properly ported AAA game title. What I have seen from AMD so far did not encourage me to even try and buy one of their cards.

> How much do you stress the GL implementation?

Quite a bit, I guess? I play a number of games, but no idea if they are "properly ported".

Properly ported simply means a renderer using OpenGL or Vulkan directly with the exact same feature set as the Windows version. Cutting corners in the port of the renderer counts against that.

I do research into rendering algorithms and that sometimes involves straying from the trodden paths. This means that I always get sceptical when I need to use a feature that is a bit more obscure. With nVidia, I rarely encountered bugs in the driver.

I know for a fact that the Mesa software renderer sometimes lies about what it really supports amd does something different and completely inappropriate under the hood instead. A good example is that Mesa claimed to support floating point textures even if the support was not compiled to avoid patent licensing issues. Instead it would use 8 bit per channel internally, which totally broke some algorithms. I had to find out the hard way because the values I read back were suddenly horribly quantized.

What I want to say with these anecdotes is that "being able to render games so that they are playable" just shows that the driver quality is passable. A great driver needs to get a ton of additional things right that are not commonly used for games.