I'm 6'4" 255lbs and I ordered the XXL. It fit nice through the chest, but looked like a dress in length.. almost 4 or 5 inches too much. Some people may like this fit, but it's not for me.
I felt like the quality didn't compare to the price tag and was overall unimpressed by this piece from Volcom. Their tank tops from last year fit perfect and had better craftsmanship.. I don't know why they had to mess with a good thing.