Oh, managing my library is quite an autistic side of me. First I remove ALL TAGS out of the original files with MP3tag, because I dislike the original ones often. Afterwards I re-tag them by "filename to tag" method. Then I rename them with "ReNamer" by removing all "(Original Mix)" mentions as I think this is totally redundant. Then I make all MP3’s the same loudness with MP3Gain (96 db). Then I send all files through Mixed In Key. 🙂
Pretty much work, but it works for me.