It was so great in search quality, number of formats it could index and performance that at one day I index the whole company file share. People showed up next to me and I rediscovered files which would have been lost otherwise.
This tool also integrated after configuration with the browser which issued an invocation to localhost to integrate local search results. As this was widely regarded as a terrible security feature to potentially tell google all about local files, reception of that feature was poor. This feature was the only incentive for google to provide the tool and therefore the tool got quickly axed.