Incidentally, I prefer the Shugenja to the Wu Jen. I'm not really sure why. Perhaps it has to do with the implication that their magic actually draws on the elements, rather than using magic to control the elements, but that's just a guess and may well be wrong.
I played a Shugenja for a one-shot once, they were meh. I still prefer a Spirit Shaman or a Druid. I've never played a Wu Jen, mostly because I never really got them flavor-wise.