Here is a summary of speed test results:
Comcast "power boost" - 28922 KBPS download 1466 upload
Clearwire - approx 1200 download - 225 upload
AT&T Wireless Modem (Cellular)143 KPBS upload 170 kbps download
T-mobile hotspot at popular Starbucks - 1400 upload and download (may vary by location as I believe this is a fixed line from an ISP called The Planet.)
Qwest (not sure which specific service and this particular IP range has a name assigned to it- so I don't know if this is the service for the whole office building or what...) - 4172 download 431 upload
I am testing out a new Internet provider and have to say the guy was to the point and provided most excellent service. I tried uploads from this company and get constant speed of 25K - even 9K when FTP'ing files up to another location. He was able to quickly and thoroughly show me that their service is actually working at the speed they profess (well very close to it) and that probably this is a problem with the ftp server, VPN or something else on the network. So now...to my server hosting company and let's see if they can be as helpful in pinning down this problem.
Next I did a test to the part of the country in which my server is located. Same thing - I got good speed on this new network.
OK so that pins it down to either my computer, or the computer at the other end, or the VPN. Right? Unless it is my hosting providers network...so I start with my ftp software. I switch out WSFTP with Globalscape - and the average speed goes up to 88-95K. MUCH better....! More here FTP Software
So, back to Comcast. Now that I have this nifty little site I run the test on comcast network. At speedtest.net I get 28922 KBPS and 1466 KBPS. A file upload still is far less than these speeds report - about 300KBPS, though better than the other provider so far.
Note that the Comcast test was not done during peak hours. I will post more results later. Comcast degrades when more people are online so I need to compare at different times of day. Basically if you live in a crowded area with lots of other people on comacst in your area your speed will be slower because more people are sharing it. If you live next to a gamer and you use Comcast, I'm sorry.