Actually no, SS is fine. I'm doing 40k+ crits (since I'm always stacking crit, even as unholy) on geared ppl with zerker buff. However, I'm not sure about that absorb bug, i'll need to test it myself and find out.
If you have an arena partner that does high burst damage (ret paladin for example), then SS is utterly useless since you'll be just stacking necrotics. But still SS is your main damaging ability so you'll need at least 2/3 points in RoR. For instance, if you got an enemy healer on low hp and you stacked enough necrotics on him, you'd better finish him off with 2-3 SS rather than stacking more necrotics. Or if you're targeting a dps class (knowing that his healers is cc'd) you'd better burst him down with SS instead of stacking necrotics. In BGs though, I'm usually killing stuff with 4-5 hits, so stacking necrotics is completely useless imo.
Anyways, I don't see the point of arguing about uh dks on this thread. Next time I'll just hide my bars when showing BG scorebards