well the flip side of that is that low poly meshes are rougher with more visible edges, so you loose detail in the surface, this tends to be particularly noticable around the edges of the figure. the best texture in the world won't fix a blocky figure though it might mask some of the evidence. There are ways to smooth meshes to some extent, smoothing in Poser can get rid of some of the blockyness, Sub-D in Studio can get rid of it completely though with that you are actually subdividing the mesh at rendertime so you will still get a hit on render time.