I'm choosing between either David Lam's Introduction to Zbrush from the Rydan Workshop
Katon Callaway's High End Fantasy Game Art CG Workshop course
I personally think that jumping right in and trying something more advanced by creating a character from scratch will give me more hands-on work and will make me improve much more. I am not sure though, as I may become lost during the course.
Any feedback as to which course to choose would be appreciated.