In my experience, the USB devices work better, remember that at the back of a comptuer there is alot of interference for the wirless ignal to contend to, also dont be fooled by the antennas, they are doing very little.
The only problem with the USB is power options (if it goes into hibernation USB devices are powered down to save power - pain in the a$$ if you are in the middle of a download. Also you have to watch where you plug it in to make sure there isnt a chance of you rubbing up against it, will damage the USB port and the device.
You can save some dollars if you go with TD - not sure about shipping though
http://www.tigerdirect.ca/applicatio...5860&CatId=369
MYK