I've been a sin or shadow since early access and I've tried a ton of variations (full Darkness, Deception, madness and the many hybrid builds in-between). Boredom is typically the main reason I try out new specs now, but I always come back to the same build & stats for RWZ.
27/0/14 and stack as much power as possible.
* yes, I do not take Duplicity. I but that point into a cheaper death field
* I have been know to run 23/0/18 for instant whirlwind in RWZ too
Melee damage bonus: 654
Force damage bonus: 995 (I had it over 1000, but I added more expertise 1240)
Now, many ppl will reply and say their build is better for this reason and that reason; however, my personal opinion is this build and stats work best. I had a RWZ last night where I did 400k damage and 240k protection (voidstar). Just not sure if the other builds can put out that type of damage and have the same survivability. Once again, this is just my opinion and I encourage you to try it for yourself as you check out different builds.
I'm favoring 23/3/15. You give up the tk throws for a more consistent everything.