I think there was a bug in an early release of the matching feature that replaced the files, but it hasn't done that in ages (unless it's become buggy again).

I think there was a bug in an early release of the matching feature that replaced the files, but it hasn't done that in ages (unless it's become buggy again). Years ago I let it match all my content, backed up my original files, deleted them from disk, then let iTunes pull down the higher quality matched versions.