Well, the more high resolution textures you use, the more slowdown you'll experience while playing the game. Is it really worth plopping on a 1024x1024 texture on an armor that you rarely see up close? For faces you'd think it'd make a bit more sense, but faces are typically well-represented by a 512x512 texture. Any more doesn't seem to make them more lively, that has more to do with how the face is drawn.