What exactly is a "proper" OpenGL card?
Surely you're not suggesting buying  a Quadro for Poser, which wouldn't make a bit of difference?

I consider my GTX 285 "proper" enough, thank you, and you can get the same answer from a whole lot of Maya, Softimage and 3ds Max users too.
Any program that has "proper" GLSL can "properly" utilize the advanced OpenGL in even the lowly gaming card. It's not in the hardware, it's in what they write into the software the video card is being used for.
And speaking of which, any Nvidia card can be "soft-modded" to act just like a Quadro, far as I know, since the chips are identical...

Not to mention, I can also use it for games, which I do, which is something a "proper" OpenGL card can't do.

In any event, who's struggling?Who has mouse jerks, lags and all that? I sure don't.