I've tried your test site multiple times and it wildly varies from 200-500Mbps. It won't let me copy the results in java window.
Here's another test I just did from KC to Chicago, outside KC GFiber network...
In the real world, you can be doing a DropBox download or sync at 200Mbps, recording 8 DVR channels and 5 other people in household doing various things that stress the network and not impact each other. Obviously torrenting is the only hard hitting app at this time (I've hit 500Mbps doing a Linux ISO). Would be hard to hit a Gbit in a household regularly but with other Gbit ISPs you may share 2.5GB with entire neighborhood and could more likely interfere with each other than the way Google backbone is apparently designed.