I download from various websites and hosts such as Rapidshare, Hotfile, etc. With my old cable internet speeds, I was downloading at about 150-200kbps per file at the same time (with a 100mbps modem, but the new one is maxed at 54mbps). Of course, downloading software directly from game/product websites garnered better speeds.
The speeds from the tests are consistent except for the testmy.net speed, which was, as you said, 8x slower than the other sites, which seems to be my max download speed from any site.
My router is 2Wire - Wireless-G 802.11g ADSL Gateway (max speed 54mbps). I will try to look up issues with it.