Got them as was pretty much only thing available that wasn't just another B8. Never had Koni before on anything as they are renowned for rusting through or leaking within a very short time, credit card on these maybe give me some more help if they rot through and leak within the 2 years.
I've never been that impressed by Koni products. They had a good rep in the 90s, but not sure how well placed that rep was.
Bilstein definitely make a superior product, that's why they're OEM fitment for some manufacturers.