One trouble I have with my mixed group is setting my macros up as they level so things are balanced. Channeling spells threw me at first, until Jamba and the 'follow after combat' feature. It's also tricky to keep up with everyone's class specific quests, but very fun. I love my mixed group: Pally tank, Pally healer, Shadow priest, Destro lock and Frost mage. While my Pally + 4 shaman group seems to flow better and I really have that down to a science, my mixed group is more fun to watch, lol.