It has never failed me. It looks alot like windows explorer. It only reads what is on the ipod, so unless you tell it to make any changes to your music, it wont. If you put someone elses ipod in, it does not overwrite your files.
It does not need a seperate folder either, so you can organize your music where you like it, and click and drag songs into your ipod.
looking like windows explorer, it is also alot more windowsy - you right click and can edit song details, ect ect.
I like the interface much more than itunes. What it does not have is playback functionality - you cannot play your music with it. But itunes for music sucks anyway, so just get QCD :D .
If you are iffy about spending $30, it maybe can be obtained for free from ... other sources. Make sure you get the latest edition though, because it is the only one that works with the ipods updated firmware. (unless you never used apple ipod updater in which case you want an older edition)