I have Dori in my Gimli-Dori-Oin deck (whose companion is a classic Dain-Thorin-Ori deck).
He's the defender, but he's just a tactics dwarf body who fills that roll better than Thalin would. Beregond would do a better job, but it's a thematic deck. I got to use his ability one time over the course of a Three Trials game this evening, saving Dain from what would have been 2 points of damage. Any other ability would have been more useful here -- actually it would have been nice to have Beregond's ability on this guy, so you don't have to pay for Ring Mail or you could put a Citadel Plate on him for a reasonable price. Ah, well.