I'm in the same boat. I gave crucible a crack today because I maxed out the vanguard bounties. Went in to Rumble as a titan and almost immediately got wrecked by another titan with a fusion rifle. So I pulled out my fusion rifle and started using the same tactics. And it actually got better. I came in 2nd 3 games straight to the same guy that was wrecking me earlier. I suppose we just have to get a feel for it.