I don't think u can call any char useless, cept maybe the fire tanks now
, Invul definetly is not what it once was specialy with the lower and caps and ED did a number on it. There have definetly been regens the have out lasted me in battle even one lvl below mine in the same missions would some times out last me. What really sucks is that the defense enhancements are only at a %20 as opposed to the usual %33 and u can have 3 , 33%(health) and u'll be at almost %95 (regen) but invul u an have only 3, %20(defense) totaling barely %56(invul) any more and u're throwing away slots. So fast healing ,regeneration, instant healing can get %95 from 3 slots while with invuls: temp invul , unyeilding, resist phys,unstoppable,resist energies, resist elements All get nicely nerfed by the lame %56 3 slot.
I still think BS maybe the most devestating single target melee attack set in the game, with the help of critical hits and build up i've never seen anyone else i've been teaming with able to single shot the amount of times i've been able to. I know i've definetly teamed with all the scrapper sets but can't vouche for their slots of course. Naturally ED did a number on this power set too but thankfully its across the board.