I just had my first go on Zbrush. Honestly, I hate the control system for it. It's so counter intuitive, you try and rotate around the model and it ends up at all sorts of angles and you are forced to use shift and drag to snap it back to normal again before trying to rotate it properly. It's obviously because I am new, and I need to get used too it, but I think I'll have to go in there and change some hotkeys and such around.
I had planned on using Zbrush to do all the skin pores, lip creases, metal scratches etc etc and generate normal maps from that. But I don't think it's wise to invest too much time into the program just yet because I need to get on with creating the models. My knowledge of Maya modelling is more than enough to see me through. Combined with the Nvidia normal map tool in Photoshop, I should be okay.
Long live Maya's Sculpt Geometry Tool!