This really complete study (2.2M, 15 pages), from the University of Wisconsin-Madison E-Business Consortium, who tested 12 desktop tools on six criteria; usability, versatility, accuracy, efficiency, security, and enterprise readiness.
Again the winner is Copernic. With no surprise the second is the Yahoo desktop search.
But the third one, is a new player for me : Wizetech Archivarius 3000. A another Canadian software firm from Vancouver who also involved in; music, MP3 and font catalog. I will come back on this soft later.