I have found a Phasezerker class mod. Finally. This thing is seriously OP, but I am having a great time with it (until it gets nerfed).
Now I am torn between these two builds:
Personal Space is a huge damage boost, but I am loosing Indiscriminate. The power of Indiscriminate is hard for me to determine. Not sure, whether it is useful at all, because I am using Ties That Bind.
Sustainment is clearly better than Clarity. But maybe 6 points in Clarity (2 from my class mod) are enough to survive the hardest content.