I certainly feel that some people find LW frustrating. Putting the firewall issues and ISP problems aside, the user is often the own cause of the slow speeds. I always got mp3 at speed above 10Ko/s on LW, except for rare french songs and unknown artists. This is the rules to get great speeds:
1)begin downloading ASAP when the results are coming as this not let time for other clients to go offline.
2)when a download is slow and has only a few sources, you can right click on the tab of your search to get more sources for download (or you can do another search with the specific name of the file which is more accurate)
3)have a preference for files that have more than one source if possible.
4)if with those things you can't get the files in a respectable time (variable as it depends on the patience of every user... ) Do another search and try to download the same file but with a slightly different size or bitrate or name.
5)Optimisation: I usually download the same file from two different results and I cancel the one with the slowest speed after the firts download is complete.
6)there are other productive ways but they don't come to my mind now

Bonne chance