Yes, MediaMonkey can rescan files for changes.

Ok, MM only syncs CHANGES to the Android device. Can I rerun sync from iTunes to MM and only bring in CHANGES made in iTunes?

MediaMonkey only Syncs changes. So unchanged files are not re-synced. There is a separate option if you want the file itself re-synced too (otherwise MMW just updates metadata in MMA).

I'm considering MM to supplement, not replace iTunes. My situation is that I have a rather large library on iTunes which I sync to my iPod Touch and my Samsung S20 Android. I had been using iSyncr to sync from iTunes to Android. It use to work perfectly until it was bought out and updated. By perfectly I mean iSyncr scanned iTunes and then would update to my Android only those things that changed. It would only copy down additions or changes like updated ratings. Could I use MM to do the same? Here is what I would like to do: Continue using iTunes to add music, update ratings and sync my iPod, do a full migration once to MM for use in syncing music to my Android. Whenever I would add an album I would add it to iTunes then rerun MM to get that album to Android. I would hope MM would only do an iterative update meaning it would scan iTunes, detect that there was only one album to update and pull that one in to be downloaded to Android. iSyncr use to work this way, the scan took a few minutes but once scanned only the changes were copied over from iTunes. This way I would have native support for my iPod and support for my Android. What do you think, would MM be what I'm looking for? If not MM, would you suggest Musicbee would be better (I'll be asking on their forum as well)?

Yes, you scan your media files on your PC, even if they're ripped or managed by another application.

However you can also use MediaMonkey to:
- Rip CD's
- Edit tags
- Sync to iPhone

I have a medium large song library (23,000 songs, 1669 albums, 126 GB) which I've used iTunes to manage/transfer songs to an iPod and iSyncr to move that same iTunes library to my Android phone. I loved iTunes (stop right there, no lectures please) and iSyncr/Rocket Player was the perfect solution to Android. iSyncr read the iTunes library and migrated everything, smart playlists, album covers, ratings, everything to the Android Rocket Player. Alas all thing come to an end, I got a new Android phone and iSyncr, now bought by some evil organization, no longer works so I'm considering MM. Money is no real object, considering how many hours of ripping and rating all of my albums/songs.

Here's what I want to do, can I do it? I would continue using iTunes for ripping new CDs and artwork, download to my iPod, rate music, upload ratings to iTunes. I would then like to use MM to scan/rescan my iTunes library once in a while so that I can download it to my Samsung Android. I know I may have to redo playlists, and I hear album artwork is sometimes a problem but I would basically like to use iTunes as my main library and periodically scan/rescan to MM so I can have a copy on my Android. This is what I use to do with iSyncr/Rocket Player. Does anyone else do this? What are the possible problems?