The photos below tell their own story. I replaced the cleats on both my pairs of "Summer" shoes recently. One pair was the usual cheapo aftermarket cleats, the other was a pair of genuine Look bimaterial cleats (the Amazon seller only had the one pair left on stock, and I was in the LBS for something else and bought a pair while I was there). Both shoes are B'wtin 500s, albeit one pair is a newer model.
The main difference before fitting was the price - the copies were less than a tenner, and the Look items set me back £15.
Both pairs were fitted at the same time, and I've done a similar mileage in both pairs of shoes. I replaced the genuine Look cleats last week - completely worn through, and had been creaking incessantly for over a week. The cheap Chinese cleats don't show half the wear. The other difference I've found is that the Look cleats are slippery - seriously, dangerously slippery. I've put my foot down a few times and had it slip out from under me, especially on wet days.
While it's a little time since I last used genuine Look cleats I don't remember them being this bad - I know they've always had a tendency to creak as they wear but the fast wear and the slippery surface is something I don't recall experiencing before. Has anyone else seen anything like this?