Then by the sounds of it you just need to practice a little more I play Titan in pvp and I've been taken down plenty of times, the sunbreaker isn't op it all just depends on what perks they are running for instance I don't use the perk which allows me to heal with each kill or while standing in a sunspot so I get taken down easier but the perks I do run allow me to hit harder so there is a trade off oh and I've also had my warlock and hunter tank better then some Titans