My ‘go to’ is +50% damage on the next two mag after exiting IB because I never reload. The effect will continue as long as you don’t swap weapons or move to a new map.
I will take +10% crit damage effect on a high crit gun (Lyuda/Muckamuck), but the flat damage bonus is going to do more work for you.
The +100% damage or +125% splash damage bonus pairs well with a rapid fire heavy weapon (the Quickie comes to mind) and One For the Road, just pop out of IB and hold the trigger down until you empty your clip.
I haven’t run into a shield anointed effect that really knocked my socks off. I guess health regen on skill cooldown is helpful for some builds. Any thoughts?