Quote: The GPU render doesn't support the full feature set the CPU render does. If we implement GPU support we end up limiting capabilities of the render. Things like limiting the number of texture maps in the scene. I'm with you on speed. I just don't want to sacrifice quality to get there.

there are no differences in GPU and CPU shader nodes, that simply would not make sense.

limiting factors for GPU (NVIDIA) renderings are:

no smoke/fire

SSS - still experimental

no open shading language

CMJ sampling - still experimental

displacment/subdivision - still experimental

and, of course, the limitations in texture maps (size and count) depending on the card you use.

https://www.blender.org/manual/render/cycles/features.html