that is when you live on the exchange, if you live more then 1km from the exchange then you would not have that kind of speed. i get 9k out of mine max, otherwise it kills my download rate. 9k upload then my download maxes...i know its in theory but that is with alot of things in your favour
You are misunderstanding.
a 384k line will NEVER EVER EVER go above 320k and 100k upload no matter how far so too with a 4mb line will NEVER EVER EVER go above 3500k download and 400k upload.
Lets put it like this.
384k Uncapped account.
If you use it with a 384k line you WILL not exceed 40kbs download. This is the maximum speed the line can go.
If you use it with a 4mb line you can get 48kbs download. This is the maximum speed the account can go.