Is there any reason to upgrade the graphics card?

I've yet to use a version of MC that really makes use of the GPU. For example, something that's been mentioned a few times, AVCHD footage doesn't exactly playback smoothly and yet my CPUs or GPU are hardly being used.

Is it worth jumping from a Quadro 2000 to a Quadro K4000? Is there anything else that improves, that helps the editing, that makes the upgrade worth it? I am referring to MC8.4 here.

Thanks