Yes i think it is, i'm using it under Ubuntu (11.04) and as far i can judge i don't have any problems with it...
I think you can remove the export option to include freebase ip-cache because freebase seems to be "dead"
Is the Polar Skulk option stilll active? I like the idea behind this but i seems to be "dead" too (cooperation with a site like Jamendo or another site would be great!)
Maybe it's an idea to "block" some extensions by default, most of them are fakefiles.
The extensions that i block in the filter are:
.torrent .wma .rar .zip .mov .r00 .exe .uue .au .snd .qt
With these extenions in my filter i almost never get fakefiles anymore!
Most people search for regular music/video files so for them the searchresults will be a lot better! (offcourse they can edit the filter to remove extensions again if they want).