BM is pretty much the spec and always has been. MM is useful if you have a full set of heirlooms and cause more threat than your pet can handle or are killing things before your pet can reach them. I can't imagine Survival would be worth it since it's mostly about damage over time and hopefully random mobs are dying too fast for that to be worthwhile.
Have you even tried Improved Serpent Sting? It kills by far the fastest.
No, I haven't even touched my hunter since Cata. Is it still good for 85-90? --- It's crackers to slip a rozzer the dropsy in snide.