I'm levelling survival on my new hunter, and I love it. Problem is you have to know what you're doing, survival is sort of the elitist build (you gotta be good with traps, able to survive without your pet, and for DPS you gotta be geared for survival).
That being said, if you have to ask, I'd reccomend beast mastery. Your pet will last longer, hold aggro easier (through straight damage and through intimidation, as well as more focus for things like screech), and since your pet is doing a bigger chunk of the damage you can slack a bit in solo.