Haven't used or seen them. Looking at price they seem like something that might be an interesting choice. Specs with the built in ballast are encouraging. Reflectors look very small and aren't going to be as efficient as PHIDs or others, but then they aren't marketed that way. The 30 watts is a bit below the 38 watts of full-size HID lights.
Finally, the 5600K temperature range is going to give them a bit more of a bluish appearance. Maybe a bit more bling than useful light that ideally would be in the 4300K range.
They seem similar to these although the wattage seems more substantial.