iTunes Match Makes Unlocked Copies
You’ll be able to upgrade all your ripped files that aren’t up to snuff — avoiding replacing, say, your lossless FLAC versions — with the best Apple and the labels have to offer, for what is essentially a one-time $25 fee. This is the right way to do it, and it’s an awfully nice gift for those of us, like yours truly, who ripped their CDs at lower quality many years ago.
It sure makes me happy to have bought CDs, rather than paying extra for DRM-encumbered 128-Kbps iTunes music, then 30 cents more per track to upgrade them to iTunes Plus.