chinese GSM module

Anybody have experience with this shield or something like it? Is the quality okay? Any red flags? Its way cheaper than some of the other stuff at nearly 100 bucks, any disadvantages?

http://www.ebay.com/itm/NEW-SIMCOM-SIM900-Quad-band-GSM-GPRS-Shield-for-Arduino-with-micro-SD-card-slot-/151121095914?pt=LH_DefaultDomain_0&hash=item232f84ecea