I say true Romero is one of the most skilled and dangerous MWs ever and Costa walked him down, dropped him, took his best shots, and won decisively. In a 5 rounder Romero's chin would've cracked and he would've been finished. Costa also weighed an incredible 214lbs in the cage, so he would dwarf most MWs that competed in the past. I just don't see anyone being able to take this dude's power for 5 rounds and stay standing. Prime Hendo would give him a good fight but I see him falling eventually as well.