I love it. I recently did all classic, BC and wotlk quests, they are awesome. Doing cata now. Group quests are bad, because it's hard to find a group nowadays, but otherwise I've had pretty good experience. May be you're trying to do too much at once? I'm doing 5-10 quests a day. Too bad that BfA is so soon, I won't be able to finish all quests in time and will have to hurry up, don't want to miss new addon time!