The NVIDIA GRID test drive is currently hosted in the USA from a datacenter on the west coast and only supported for connection by North American users. Your experience will vary based on your location and connection to the datacenter. To help you evaluate your connection quality the title bar of the GRID Workspace application displays ping time, frame rate and bandwidth consumed.
In the last months we have extended the GRID Test Drive internationally. Now we have data centers in Oregon (North America), Tokyo (Asia), Singapore (SE Asia), and Dublin (Europe).
When selecting "Best Experience" you get connected to the closest data center for best user experience, but you can also connect to specific locations if you want to evaluate the effect of different geographic locations.