Adopt a little patience and let TuneUp do its thing and we think you'll be impressed with the results. Its database is very impressive, its "best guesses" of what was what were invariably spot-on and it integrates additional artwork seamlessly into your library. Even tracks with absolutely no worthwhile ID3 information were successfully identified.
Perhaps the most useful feature of TuneUp though is the ability to re-purpose information already present in your current library. Ever put a compilation on your iPod only to have it create an additional 30 artist entries, each with a single track? Within the settings menu here you can stop this from happening, as well as blasting away any "artist X featuring artist Y headaches".
The de-duper function removes any doubled-up tracks or albums - another feature of our test collection that was successfully zapped. It shows you the two (or more) different versions, including their bitrates, to help make sure you don't zap the new 320kbps version rather than that 128kbps rip from back in 2005.
The Tuniverse feature is the one tacked-on bit that might be argued to be superfluous, but it's neat enough not to irritate even if it's of no interest. It offers information and videos from the artist, and concert dates. This isn't particularly tailored for us UK folk though, so you're probably better off with a standard web search for the latter.
It does the job, and does it well. But is it worth it?
TuneUp sells for $50 online, for a life-time "subscription" to all four services - the cleaning of track info, cover art gathering, the Deduper and Tuniverse. You can opt for a year's functionality for $10 less, or buy one of the three key library-changing features for $30. However, as there's no bundle that offers cover art and track cleaning - the essential bits - the full package is by far the best bet. A boxed version is also available for £17.99 from some of the major online retailers - although it's not clear whether this includes the Deduper function.
It's the cleanest, most enjoyable solution of this kind we've come across, but we can't ignore solutions like Magicbrainz's Magic MP3 Tagger, which uses CDDB information to get the same results. The UI is not a patch on TuneUp's of course, and TuneUp will link-in with bit-torrent clients to pre-process new tunes (clearly aimed at folks who get their tracks from less-than-entirely-legit sources), but you're paying a premium - for a premium service. If you're not convinced it's worth it - having suffered with the irritations of a disorganised music library daily we think it is - there's a demo version that maxes-out at a limited number of actions.
Reliable, easy to use and boasting an attractive interface, this is the most pleasant MP3-fixing tool we've used yet. It's not quite as quick as advertised and has to compete with some completely free alternatives, but if you're a music nut who nabs tunes from a wide array of sources it's well worth dipping your hand into your pocket for.