I prefer using SimPE to determine the identity of files, because I can look at the texture, text entries, etc, etc. Full textures are much better to look at than the thumbnail from Clean Installer. (I just bit the bullet and went through all my old walls and floors the other day...or so I thought. There are still people uploading wall files with their wall_hexgibberish filenames.
)
Of course, I did have everything narrowed down before that. I used Delphy's Download Organizer to do mass file moving of various categories. I think that recognizes more categories of files than Clean Installer. Though there's a little wonkiness with compressorized stuff, I haven't had huge troubles using the thing after compressorizing everything in my downloads.