Are Nouveau drivers similar in quality to Nvidia drivers?

[Nintonito]

looking at the pixel C,  and I've been informed of the use of Nouveau drivers.  Does this have any real impact on driver quality?  I've heard some rumbling on xda that some games that do properly use Tegra's 3.1 + AEP implementation instead of desktop OGL still has graphics bugs (example being the talos principle).