Then why would it take you 10 hours to download 720p? Hell, I can download a full dual layer BD (50GBs) in 5 hours.
It may be because of ISP caching or that "feature" that bursts download speeds at the beginning but slows it back down for sustained transfers.
When I had Comcast I'd see similar bandwidth tester results but when I'd do large downloads it's be more like 1 MB/sec.
Since I switched to FiOS (20/20 service class), what I see in actual downloads is what I see in the tests. Verizon sucks hard as a company to deal with, but the service is great.
John