That is what I do as well. But I am pretty picky about perks and what I want to actually level and try. It would have to have pretty perfect perks for me to level. And with exotics I try to wait to get a 310 drop before rushing to upgrade them. Some guns I don't really level, especially if they are for Crucible. I don't play much PVP but Regular crucible seems like a great test bed to see if you really want them for IB or Trials without having to worry about their level.