first of all Buggyman, calm down, nobody is arguing that you aren't getting the speeds you say you are getting
I fully belive that you are getting what you say you are getting through your usb adapter
for some USB works perfectly, ISP's really push them because they are the Easiest to install, no need to crack the pc open and install a new pci device, they are much simpler for novice customers no doubt, and for some it works PERFECTLY
However most of us that also have Cable or DSL also have LAN's in our house, so we already have 10/100 NIC's and such, and of course we all want our LAN at 100Mbps so we just use our NIC, a switch or a router and share the Internet connection etc....
And for some users using USB is a nightmare, as someone stated Device drivers and compatibility is an issue, along with as you stated USB design, it's just not intended for broadband connections, Where as NIC's ARE they are built for network communication from the ground up.
I have no doubt USB 2.0 and FireWire will have a BIG market place for networking, it's MUCH easier then having to install a NIC cause you don't have to crack the case etc... But RIGHT NOW at this particular time on this Planet NIC's are a better option because of stability/drivers/speed and cpu utilization.
NIC's from 3Com have some interesting features such as Parellel Tasking and Wake on LAN and such, and have very powerfull processors on them themselves.
USB uses your CPU for processing, and in intense multiplayer games and such it's better to have all the cpu power you can have, therefore using a NIC where it does everying on the NIC gives you some free resources for whatever you are doing.
They both have plusses and Minusses
Right now NIC's are better
In the future? I can't say, cause we aren't there yet
