I need to sit next to a pianist regularly and I don't have much space behind the keyboard. So a normal chair is always a problem.
This seat is perfect, it is small and it is softer than a normal chair. Of course it is not as good as a real piano bench (which I also have), but it is a great extra seat that doesn't take up too much space.
The reason I rated "good" for stability is because with this seat, you might wiggle forward because its weight is low. But that's probably a personal issue.
* Ceny zawierają podatek VAT. Do ceny artykułu(ów) należy doliczyć koszty wysyłki. Oferty ważne do wyczerpania zapasów. Za błędy w opisie i innego rodzaju pomyłki nie ponosimy odpowiedzialności. CK=Cena katalogowa produktu