Not really much of a problem, especially not for videogames, since meshes are often split into head, upper torso, lower torso etc. 2gb will do good, I work personally and professionally with that. All characters runs smooth. This should apply to mudbox too I presume. Polypaint is the way to go if you can, never any trouble with seams, and an actual highres mesh in front of you as you work. Plypaint in Mudbox 2 wins over zb though, (for only a while I hope:) )
Actually partially easier for games, as artist’s imaginary texture sizes only lasts until the optimization phase:p
However, texturing the actual lowpoly character, does not work at all in either of mb or zb, you really need to have bodypaint (or PS) to texture that. And bodypaint+photoshop was a dissapointment to me, considering bodypaint doesnt support all layer features from PS, which can be a huge problem.
My personal advice is Zbrush and Photoshop. But of course, MR/ZB doesnt really matter, its a question of taste. Bodypaint is nice, but you really can live without it.



