I've been running 8/31/2
for the last few days. I switch back and forth between high energy cell when I need more damage and ion cell when someone needs to be guarded. I wear the combat tech set. Still trying to decide between a shield or a generator.
It's fun. Decent damage. It's versatile. It's mobile. And it reduces smash damage by 37%, making swarming smashmonkeys just mildly unbearable rather than totally overwhelming.
I think it's a better PvP "tank" build than going far up the shield tree. Shield is very PvE focused. The only thing I miss is Storm, and Hold the Line is reasonable substitute. And I have the added benefit of being able to drop people, especially with Pulse Generator when they gang up on my guarded target.
It's probably not as effective as assault, but I'm bored of assault.