Full carbon fiber 29er suspension mountain bike from AliBaba
Ask yourself this- would you buy a car off of Alibaba to save a few bucks, or would you fork over a little more money and buy a Honda/Toyota/whatever?

Buy the name brand bike. If your Alibaba bike's headtube snaps off on a gnarly high speed descent, who's going to do something about it? Not Alibaba, and good luck getting the manufacturer from god knows where to do anything about the catastrophic failure of their no-name bike. 

Buying the bike pictured is a total gamble, not just in terms of your money, but in terms of your safety as well. Play it safe, pay a little more, and stick with the Giant- they've got a great reputation, they make great bikes, and they back them up.

Alibaba is for widgets. A bike is not a widget.