Their linux OpenGL drivers often outperform their Windows drivers.
As for AMD, the open source Radeon drivers are pleasant to work with, and on some hardware perform as well as Catalyst.
The open-source drivers are not on the same performance level as the closed-source drivers, though the AMD open-source driver can be classified as "usable" (or better) in most contexts whereas the nVidia open-source driver has many issues since it depends far more on reverse-engineering the GPU's programming interface. Intel has the best open source driver of all of the desktop vendors (since the open source driver is their official driver) but its use for anything 3D is constrained by the relatively weak performance of their GPUs.
7 years with Ubuntu, I don't see that, what is it you're doing that makes it so difficult for you?