I have iTunes Match and for the most part it's awesome. I happened on a bizarre issue a few days ago though.
The music in Every song of 1 particular Album (Cake - Prolonging the magic) is gone. No other songs experience this issue and the songs play fine and contain all the music when playing from my computer. I've manually downloaded the songs from the cloud onto the iphone and no dice. Removing and letting it play from the cloud results in the same issue.