I think I have a medium/large heard, at least when it comes to the V-80s. I can only wear them comfortably with the metal arms pulled all the down on both sides. My ears are medium sized. When I first got them, they hurt. They hurt to a point where I couldn't wear them for more than 20-30 min. at a time and I was even contemplating returning them because the pain was just ridiculous considering how much I had spent on them. With a little patience, a lot of bending the headband, and some time(2 weeks give or take) I was got them to behave. Now I can wear them for hours and most times they kind of melt into my head. Approach them the way you approach a pair of new shoes. Uncomfortable until they're perfect.
Thanks, I finally decided to buy a pair and hope for the best. I'm definitely optimistic, and I'll make sure to give them plenty of time to get a good fit before considering getting rid of them.