What some find fault here because the supposedly loose armrests, here what must be clarified:
My desk at work, I have a chair for about 1000 EUR, as can extremely much set and inflate lumbar support, etc.
In this chair, the armrests have as much game as the racer and that's by design.
If you had stuck armrests without leeway in fender benders and collisions with desk etc., this after a short time broken or worn out at suspensions, whatever chair would.
Furthermore, it is for the elbow (or wrists) healthier if they have a more flexible edition.
Anyone who has worked a long time with a chair with armrests rigid, know what I'm talking about. ;-)
I have seen many chairs mounted and can only say that this in terms of quality, comfort and finish a very good price / performance ratio.