I have my DT up to G9 and have been running him with Palp (L), TFP, Boba, DT, Shore with pretty decent success (top 5 in a Aug/young shard). My primary problem is needing more gear to make up for the stars and low hp pool. He doesn't do alot of damage and you dont get the benefits of deathmark until you have killed someone but his Daze/doubleattack/stun has been pretty consistent for me and he does move at a decent pace under palp lead once he gets to finally go once. The TM from laying debuffs helps and his aoe dispell is also useful. For now he has replaced Sun Fac and I dont miss the extra tank (should get better as his gear climbs and I can hopefully eventually star him up) but I can see Krennic needing a double tank to help with surviving things.