Do you guys like working on OSVs?

Hello Gents, I am currently working on research ships, but thinking of a change to OSVs. I have heard that you do a lot of pumping, basically tankerman work, and not much repair. How true is this, and how are the working conditions? do you work a lot of overtime? I have done some searches, and get the general idea, but I enjoy wrenching more than pumping, so having some difficulty making up my mind. Thanks for any input you can provide.