I'll start off with this. I've been using Zygor Guides off and it's mostly been a very helpful tool. The guide has grown with the game and now encompasses achievements, pets, mounts, and many other things in addition to the main staple, Leveling. It gives you step-by-step instructions and uses a "gps" arrow to your objectives with a reasonable degree of accuracy. They've even automating many functions such as accepting and turning in quests, selling trash items when you talk to a vendor and auto-equipping new gear if it's better than your old stuff.

Since the beginning the guide has always been a mixed bag. That's not necessarily a 'bad' thing, just a fact of life. Azeroth is a HUGE and complex place, with thousands of quests and ever-changing locations, flight paths, portal locations, and added content. It's no easy thing to keep up with it all, so I expect some issues.

The retail WoW guide is very complete, and I use it regularly for solo dungeon runs, leveling, and especially achievements. It's a GREAT guide!

The WoW classic guide is still a work in progress, too, so I hope for improvements. The only thing I really feel the need to complain about is that the horde leveling guide takes you to Silverpine Forest instead of the Barrens. Why take us to a place with few main profession trainers, no secondary profession trainers, no forge, and no anvil instead of the Crossroads? That hurts.