Defense wise on my BC I run in FP. I hit a PRR in the 50s. I have around 600 HP in LD with a 16 con. Between the PRR, blur (from enhancements), and a little dodge I am not hit all that often. The big thing with these types of builds is to look at the aura heals as a form of DR. You are more vulnerable to burst damage though.
I am not saying this will be the new ubber max DPS enhancement. I think it will allow for some interesting builds that should be able to hold there own in any PUG or guild run. I think the main thing that will detract from a build like this vs a BC is that the BC will still heal the group just by being present. A EK/PM build will be completely on their own. That is a bad spot to be in as a front line melee.