Imp revenge is good for an aoe tank spec.
I still have it in my single target spec, I should probably move those points else where, but honestly once you get the core talents in it hardly matters where you put the last few points, unless you have a specific utility job in mind for a fight. Honestly I'm not seeing any of those in DS normal.
The absorb from the 2pc is a shameful 3k ish on average. I pop revenge when its up to get sword an board procs and on progression when I feel every little bit of mitigation will help, though it probably is not doing much.
Its a lackluster tier bonus, but since 4pc is pretty much required for raid wall you might as well squeeze a few revenges in there.
There is something so appealing about backhanding someone across the face with a shield.