I absolutely love tanking, but I'm trying to pick my off spec and need help deciding. I see a lot of QQ about Ret dps. How is it around my level? Are the issues just at 85?

I have a Warrior buddy who tanks/dps and we also have a pocket healer, so I'm not really interested in a healing off spec, but if ret is turds I would rather not do it. The plan is for me and the warrior to take turns tanking every other run.