with the disclaimer that I have never ridden a Mark V pro and the suggestion that you ride both of them and make your own decision about what you like the best, I want to say that I am constantly upset with my surly steamroller (although I love it) for not being a big block. Basically, my opinion should be meaningless to your decision, but I feel compelled to express it because I really really like the big blocks. also, you might miss having a rear brake one day. AND I'm from grand rapids originally and think a big block would look awesome locked up around east town somewhere.