FYI: quests can only be completed by one person in a party at a time and that person has to get the killing blow on the boss. At least at early levels, say <10, quests make up most of your XP so do not play with a group. Can't speak for past 10 because I wanted to play with a friend or two and it just wasn't worth it for us.
Some of the quest instructions are misleading (location wise) and/or don't indicate the level (walked into a level 8ish quest right after a level 4 quest while thinking it was a level 4-5 quest).
