I have a buddy that got one for his iPad 2 and he considers it a mistake. They might seem well made out of the package, but soon the materials will start to separate. The magnets are not half as strong, which can lead to the iPad slipping off of a table if not careful. I have seen pics online of them just flat out breaking apart.
I let him compare his to my apple smart cover (poly) and the difference was night and day.
I agree that the apple smart covers are a bit pricey, but if you want a smartcover, go with apple. They really are high quality.
I think I like the Poly over the leather. The leather ones seem to get very soft and they can discolor very easily, however if you like the "character" that leather gets over time then go for it. I feel like the poly smart covers stay a little cleaner.