It absolutely is from what I've heard. There are devices where the Mali GPU works well in some games/apps with one version of the OS and are severely broken in a newer version because the driver broke a lot of things to make other apps work.

It's one of the big reasons I'm hoping that with efforts like the driver for GPU for the RPI being open sourced that we'll start to see some more consistent drivers for mobile chipsets.

I more fear of a world like DOS/W3.11-era games - that games ship their own drivers like back in the old days it was done for soundcards...

Or move the whole rendering to a server in the cloud, where any awfulness is at least going to be consistent and predictable. This is what NV were (are?) pushing as "Grid", though I haven't heard all that much about it. They say they can keep latency at acceptable levels, but it strains credulity a little bit.

I think it is a real solution to the cheating problem too, far better than say VAC: http://games.slashdot.org/comments.pl?sid=3105&cid=1442601

Yeah. Piracy too.

I have the misfortune of developing OpenGL ES stuff. And I cannot overstate how bad the drivers are.

It's pure bliss to use normal desktop gl implementations because they don't constantly crash on you. They don't have weird breaking bugs. They don't leak memory like no tomorrow. They don't play fast and loose with precision. They don't have absolutely retarded performance regressions.

Basically the drivers only work if you use Unity or some other well known engine. The driver makers don't really bother making real ES drivers, they just make something that doesn't crash Unity.

I could go on and on about this.

Speaking of Unity + Android, our mobile game is seeing a huge increase in crashes on Android 4.4.2 (the latest) on Samsung GPUs (PowerVR). Apparently it's due to a bug in the driver. So, I guess the mantra of "don't crash Unity" doesn't always succeed =)

John Carmack has commented on the replies section that is much worse.