Enemy damage resistance lowering feats/powers

akta#9913

My "resistance ignored" is at 62% so is there any reason to keep feats or artifact powers or companions that " lower enemy damage resistance by 5%" I don't understand if this included in what my armor penetration covers or if this is additional damage resistance that is being lowered.
I ask because I'm trying to decide what is most beneficial from these three options: increase damage by 5%, increase crit severity 5%, decrease enemy damage resistance 5%

armadeonx

Enemy DR can go into negative value so they do still work.

For crit severity to beat damage, you'd need your crit severity to be over 100% and have a v. good crit chance. Usually increased damage is the way to go with companion active bonuses.