Crashback Arms - any good?

[Fiddybux]

So I'm thinking about buying these Crashback Arms for my X5.

http://www.iq-tuning.ch/en/crashback.html

What is the general opinion of them?

I've heard some mention that they wear around the hinge pin and become a bit sloppy, but that's the only bad thing I've heard so far.

Is the handling / steering response affected if they 'flex' a bit?

Thanks all.