I've read the manga (despite how long it took the third to come out...) and I rather thoroughly enjoyed it. I'd go so far as to say it's my favorite part of the entire .hack franchise.
It was much lighter than either the games or SIGN, and had a much more engaging (I thought) plot. The characters are more likeable, and very amusing and inspiring. The anime version wasn't as good in my opinion, as they totally avoid Zefie and stuff.
Also, if you're strongly against incest, the anime makes a ShugoRena relationship a little more evident, so be warned.