I upgraded LimeWire and found that it included advertisement banners. This was the only noticable difference... except: EVERY Mp3 file that I down load ends up in this nebulous format that is less convenient to open, and impossible to burn onto a CD. There is NO difference in search or download speed. There is no positive reason to upgrade and two very good reasons you should not upgrade. I'm going back to the previous version. I considered becoming a paying user, but who knows how usefull LimeWire is after you pay? Their promises for the new version certainly didn't come true.