Most, if not all, 3d programs do more or less the same thing. People get comfortable with what they know best. My work flow is as follows:
3ds Max-
low to high poly creating, figures, clothes, props, etc.
ZBrush-
detailing of all created objects from Max, wrinkles, scars, morphs, engravings, etc.
Poser-
boning and joint parameters, cr2's
UV Mapper Pro-
texture maps and groupings
Photoshop-
textures and post op work from renders

(next part said with heavy sarcasm)
That's all there is to it really.

Comitted to excellence through art.