It doesn't require the browser to be always on, unless you want to download something (which is the same as a normal download). Do you mean it's better for the health of the swarm for a particular file? Otherwise I'm not sure I get your point.
> Do you mean it's better for the health of the swarm for a particular file?
That is one of the main points. Some files are shared by thousands users and can be downloaded in seconds, but others are much harder to find, so that I like to keep the client on to help other people getting it quickly. I usually am annoyed when a file with a single seed reaches like 97% then it dies until the following day because the seeder had to turn off the PC, so I try to avoid this, especially since it costs me nothing as broadband is flat and the client runs on a machine that is always on.