I sit time over two years every day in this chair and am very satisfied - and fallen over I'm so never. The quality is absolutely OK for the price, for at home I have now ordered an after the last 100,00Euro chair has also bent.
When I finally stumbled on a review of Stiftung Warentest, I could not believe "Poor !?" as test result for my favorite chair.
No idea how that have determined the result. In our company we have eight of these chairs in use and there were never problems.
From me, there is a good to very good and therefore four stars, but only because I find the backrests impractical.