It would not be useful. You need to understand that, when you are downloading large files, no matter how fast your Internet connection is, you will rarely get more than 3 mbps speed. That is because your Internet connection is rarely the bottleneck. The servers you are downloading large files from are usually overloaded and, when they are not, they also do not have infinitely fast Internet. Furthermore, the server is usually somewhere in America, half a world away from you, and there are countless other bottlenecks.