Going Pro won't solve the problem of spam/fake files that are on the network.
For more info, follow the links in this thread:
Fake files showing up in search results (Connecting for ages with many hosts & then Need More Sources when trying to download a file.).
Look up the files with
Bitzi before downloading to help sort out the bad ones. Also preview files when they get to 15%.
The Basic(Free) version of LW is very good and buying Pro won't solve any problems. Pro connects to more hosts which can mean faster d/loads and better search results, but the differences are subtle and most of us consider buying Pro a donation to help in developing future versions of LW.