What's going on?

I started using Webroot SpySweeper after hearing about it at work. I had previously been using Ad aware and Spybot S&D to combat Adware and spy ware. I was quite suprised at what it found. I first updated and ran AdAware, and Spybot S&D, and cleaned what they both found. I then loaded Spy Sweeper and found about 50 other traces, and other nasties of the like. I later updated it and tried again. Nothing found.

Just wondered if this program is worth the time, and if it can really compare to what I have been running. Some of the guys @ work swear by it.