Few things I've noted whilst testing
- the 10% leech from pet is incredibly helpful, I rarely go below 80% health even when AoE pulling.
- I feel often I have to weave kill commands and raptor strikes as I go low on focus very quickly, flanking strike seems like a must for focus starving issues.
- I feel like you'll need a certain amount of haste for the build to flow nicely. when I pop berserking the spec feels extremely satisfying to play and flows incredibly well, without berserking it's a little stale.
- Serpent sting duration seems a little short, though it costs nothing so is fine to refresh.
All in all playing Survival then playing my UH DK, I can't see why you'd pick SV over UH at current time. Obviously 120 I haven't touched yet so can't comment on that, for all we know Survival could scale incredibly well at 120 and be amazing with gear and UH could be turd.