The games are different and different skills are required as Wild Bill points out. I really only play stud online both because of where I live and because I can really only see all the cards on my computer screen as opposed to a table.
I play both stud split and Omaha Hi-Lo, mostly the latter recently. I have found some juicy online Omaha lately.
I think it helps your game generally to have an acquaintance with different games. At the rec.gam meetings I've attended I've enjoyed the low limit CHORSEL (Crazy Pineapple, Holdem, Omaha split, Razz, Stud, Eight or better split stud, and Lowball).