I'm introducing my girlfriend to WoW & the plan was to just party up & do everything together (but presumably have to kill twice as many things), but someone told me that in Vanilla it's terribly inefficient to do quests in a group. They said the quest item drop rates are reduced when partied [not that you have to kill twice as many things, it's more than that] and that the XP is worse than a 50% split.
I was assuming that quest drop rates are the same and that experience is cut in half, so we'd just have to kill twice as many things [around what we'd have to do solo anyway].
Is it worse than that? Should we quest together but just out of party?