Another tip to consider, get one team to 90 first, then farm heroics to buy the heirloom sets. It makes leveling a new team infinitely easier, both from the exp bonus, and the automatic stat upgrade every time you level. With RAF alone, you outlevel your gear so fast that sometimes you wipe, slowing down the whole process. Having full heirlooms on all your team means you can largely ignore gear and just power on.