I have Once Care installed and operating. However, when I periodically run a scan using Ad-Aware, I still find situations where Ad-Aware identifies and eliminates what it referes to as "critical items."
OneCare does not block or remove 3rd party tracking cookies as these can be blocked in your browser settings. These are typically reported by Ad-Aware and other similar products as critical items. It is still a good reason to run another program like AdAware on occasion as no one product will protect and remove all adware and spyware.