I have one, primarily because Campag don't do the ratios I wanted in 10sp.
The quality is fine. The cassette is made of individual sprockets and each and every one is replaceable. They are ripe for chopping and changing the sprockets as we used to be able to do in the old days with screw-on freewheels.
The coating seems to be better than my previous cassette - 2006 Centaur - and is definitely shinier. The Centaur was dull and boring. Even my old Mirage cassettes were nicer looking than the Centaur.
Campag cassettes are "timed" by having ramps to aid shifting. I was told that if you mix and match Campag sprockets they don't change gear too well. I don't know about that, but I was worried about the Miche as it has no timing ramps at all. I need not have worried, it changes gear as sweetly as any Campag I've ever had!
Swapping to Miche was an inspired move for me. As good as Campag, looks nicer, and has separate renewable sprockets.