If you want super-easy rigging, yes, every extra polygon means extra work. if you want realism and lots of morphability, then you need every polygon you can get.

Most of my characters are based on a V3/V3RR hybrid: I matched a low res V3RR head on a standard res V3 body. This gives me the "full-detail" body while I don't need the full resolution head most of the time. With about 50k polygons, that mesh is still light enough while detailed enough for centerpieces. I have a range of weightmapped low resolution meshes (Down to 1K) for background duty.

Again, all figures are optimized for Poser (and to run on my low-end laptop), making full use of all the things that Poser can do. I try to use weighmapping as much as I can and only add ERC-morphs if absolutely needed, as this makes cloth creation easier.

Remember I'm only an amateur with very limited ability and time. In the right hands, a professionally made Poser figure could easily "out-bend" even the latest, greatest Genesis figure. Poser's rigging tools are actually THAT good.

But as I said, I think that opportunity is long gone. It'll take quite a bit of time and especially a lot of money to create such a figure.