iTunes Match accomplishes a few things for me:
- Updates my collection to 256 kbps aac files (higher quality)
- Backs up my collection online (iCloud)
- Makes it easier to use other Apple products for my music collection without needing to download everything. This makes it easier to use a lower capacity laptop, iPhone, or iPad.
It’s worked pretty seamlessly for me and costs $25/year, although you only need one year if you just are interested in accomplishing #1 above.
Updating to 256 kbps
I followed the Macworld instructions to create a Smart Playlist that shows just the songs needing an upgrade (see picture). Hold down option key when clicking the plus to add the conditional rule for iCloud Matched or Purchased.
Then I selected all the files and deleted them, making sure to NOT select to delete them from iCloud. Then I downloaded the files over a couple of days.