I've been a support hybrid since before the patch, meaning I've had max revival and party MP recovery even when their use was pathetic.
Still, as things stand right now, I generally have no problem keeping a party alive if they are somewhat competent. If I had the RB heal (Not that I ever will because RB fails) I can see myself being a complete stand in for Eirs during your typical 4 person party. Far as raids go, Eir won't be replaced by Kriegs anytime soon as a lot more deaths occur far more rapidly in those than anywhere else.
Overall though, Krieg really can be quite the support character now. If you deposit points into RB heal, you can max Party HP recovery without any issues at all. RB heal can be used without sacrificing HP which means you'll never get yourself stuck at 0. I plan on maxing Party HP recovery but it won't be maxed until I am level 85 so it's going to be a long time. As it is right now, the HP cost to HP gained ratio is very much low enough to warrant getting this skill higher up. I use this skill every time it is off cooldown as a nice AoE heal to my party-- at max, I can foresee it being a amazing skill both for fake ressing and party HP management as well overall survival.
"There once was a boy who dreamed of being a hero. Who believed sincerely in the battle to banish darkness from a world of light... but light and darkness are equal... and where one exists so too must the other... and when the boy finally realized this he had taken the first step toward being a true hero."