Well, in the program I use, I usually leave all the surfaces as they are, some can have up to as many as, oh, 10 vertices or more in the mesh. When I export as a .obj, it triangulates the surfaces automatically, and it worked fine when I used it, but I guess it wasn't so friendly with other programs. So, I chose how I wanted them triangulated and reexported.
I use AC3D to make my models, then I open the .obj in PoseRay to add spec maps, bump maps, and all those other goodies because AC3D only allows one texture at a time. Anyway, I'm just glad it worked this time.
Also, that render makes her look fantastic, what program do you use? AC3D is only about $50, and PoseRay and POVRay are both freeware, so I've been doing all my work on a super small budget compared to some people I know.