I'm sorry Warren, but the predetermined, precached tests for Hughes aren't the only thing we use in the real world. Those speed tests load the actual times it takes for information to go up and down without "adjusted" speeds from Hughes. Those are the speeds I get when I load ANY OTHER PAGE besides Hughes speed test!
The tests on the Hughes system isn't cached, and is close to real world usually. If you want to use a third party, use testmy.net instead of speedtest.net.
As far as speeds, they do fluctuate greatly from mid-day to the late evening, this is due to network congestion. Hughes isn't changing things in the background to suddenly improve your speeds temporarily.