I'll be leveling as survival with a BM offspec for elites/rares w/e.
The problem, for me, with leveling as BM, is that if you just walk up to mobs and press Kill Command you'll end up one-shotting the mob and not get the tag (exp, loot etc). I feel it's a lot easier and a lot more fun running around firing Arcane Shots and watching mobs die as I run with Serpent Sting.