I totally agree.

Good ways to reduce the VM use is:

1. Tip: Purge the Downloads Queue! (click on blue link)
2. Share less than 2,000 files, however if large files such as videos, then even less.
3. Disable Ultrapeer capabilities for a start. Go to Tools > Options > Advanced > Performance & disable UP. Can also disable all options on that window.
4. Set both uplds & downlds to autoclear.
5. Close all LW windows you don't need open at that time. eg: Connections window.
6. If you're not in front of your comp, then hide LW in the dock.
7. Don't use the Resume button on all incomplete files. This can have side-fx such as affect LW's connection quality. May queue your files for much much longer. This will also stress LW & your comp. "If" you use Resume/Find sources then just apply it to a couple or so at one time.
8. Try to ensure you have plenty of space on the system drive. Easier if you have more than one drive. eg: I moved many applications across to another drive (those that will run from another drive.) I also had my iTunes music and many other types of personal files on a different drive.

Quick fix to LW slowing down your computer is to close it and re-open it as that clears all the VM (Virtual Memory) that it uses from your system drive. To check for how much ram and VM LW is using over a period of time, open the Activity Monitor from the Utilities folder.