My warrior made level 85 this weekend, having gained over 90% of the xp from level 80 to 85 by doing archeology. Using rest xp that wasn't all that much slower than questing, and as I have too many alts and didn't want to do all the quests several times, that was a good way for me to level.
As a way to get gear, archeology was a failure. After hitting 450 skill, I went through the 1,200 troll fragments I had gathered, roughly equivalent to 100 dig sites, and of course the epic 2H sword didn't drop. That might just be bad luck, but other people report similar bad luck with many more fragments, while some people just get lucky and find it fast. Like all low-chance random drops, luck is not reliable enough for a gearing-up strategy.
I did however make crazy money selling Tol'vir Hieroglyphic for 1,000 gold. And got a few blue fun items with various effects, including a pet and a mount. So combined with the leveling, I don't consider I wasted my time with archeology. But if you are already level 85, I'd advise against doing it just for the epics.