I've used Brian's guide, and, to a lesser extent Joanna's.
I think they were worth it at the time.

Nowadays Questhelper does the job well enough for me. The only real advantage to the guides that questhelper doesn't provide are what quests to AVOID. But since that was mainly from a solo perspective it wasn't as applicable to multi-boxers. The guides offer some other slight advantages to help you optimize your path as well as things like "make sure you save all your xxx, and be sure to buy an xxx while you're inn xxx"... a few little things like that to speed things along. I'm not sure those niceties are worth the price any more.