The GPU_rasterization in general is disabled (except on the devices listed above) so that most certainly isnt the problem.
I can't confirm the performance problems.
sqiddster till Chromium 36 will arrive onto Node-Webkit it will probably take a few months, and till then, i think it at least is fixed in Chromium itself,
so that would mean that if it is fixed in Chromium, we can fix it in NW without any problems (probably).
That results in, that it probably wont be a problem nor for you, nor for me.
After all, it doesnt seem to be a common problem, so what could be the cause for this?