Since it is too early at such a product in such a short time for a meaningful evaluation, this applies only preliminary and is overall considered positive. The chair seems to be of good workmanship and currently holds at but intense stress what it promises. If that is in half a year yet so that was the purchase at this price is a true Okkas Sion and definitely deserves all 5 stars!
So here's another vote for the last 20 months usage: The chair is still alive and is in daily use - therefore the statements made above. The chair is good, the price is good. Worth every penny