I love mine but I have never owned a Gitzo carbon fiber model to compare it with, only a Gitzo aluminum model.
I think it's very good quality and when compared to a Gitzo model with the same weight, max load, height, etc... was almost a third of the price. I bought mine from LinkDelight on ebay. Even with the international shipping cost is was still less than half the Gitzo price. Excellent value IMHO.
The only minor negative for me is that the foot spikes are not built into the bottom like my old Gitzo which had rubber feet over the spikes. So you have to unscrew the rubber feet and screw the spikes in.
The other possible downside is the leg locks are twist and not flip levers. But I don't believe any Gitzos are flip levers either. It does have the sealed twist locks but flip levers hold up better when exposed to sand, dust or mud which may or may not be an issue for you.