I never really liked Dudley's design, but in the right hands he can be devastating. It's always fun to see him fight Balrog, lol. Karin is great in A3 too, she had a lot of character to her and she stuck out from the rest of the cast. From what I've heard, she's pretty good on SFV but I haven't had any experience with the game yet.
Do you play Mortal Kombat at all?