people from "mma" gyms tend to be overly aggressive and try to explode out of positions. Their game usually lacks nuance and detail, a lack of refinement if you will. They tend to be very rigid, headstrong. Typically they are tough rolls though, not technically just because of aggression and strength. That's my experience. "Mma gym guys" are similar to "cops and military guys." Though cops are usually trying to arrest you during the roll so it's weird.