Hmm, Match worked somewhat on 3G earlier this week with it set to "off" though. It had to buffer a lot though and some tracks were grayed out.
I don't know enough about how match works to know how it worked when set to "off" but maybe turning it on will help.
The Music app (and the Podcast app) has an individual Use Cellular Data toggle as well, that was probably on. They do the same thing.
Also, they weren't kidding when they said this new display has richer colours, 4S looks washed out by comparison.