I downloaded and installed it and let it index a bunch of folders (not my whole My Documents folder, mind you...) and my Outlook pst files. The intial estimated index size for indexing everything was 14 GB! However, paring things down (I run exifPro so removed my 15GB My Pictures folder, for example) got the estimated index size down to 2.8GB. However, the final index size was 398MB, which is about the same size as the Copernic Index. I'll say this: WOW! It's fast - X1 and Copernic drove me crazy in that both of them took a while to display previews of found files (in some cases a LONG while). Archivarius seems to be very light on resources, too. For instance, Outlook was being idiotic about warning me about a program trying to access it and putting the breaks on indexing. Eventually, after I managed to miss one such dialog Archivarius reported an error and stopped indexing at 81%. I'm completing my base index and it's using almost no (0-2%) CPU, 11MB of RAM and 45MB of VM/Private bytes. This contrasts with X1/Copernic which were good for much, much more resource hogging... I'm going to play with this for a few days but I think it's a keeper (and I qualify for an academic licence - yippee!).