I bought this product back in Oct 2020 and have used it almost every single day since then. Even after almost a year and a half of 8+ hours a day it is still firm and holding its shape. It has been a literally game changer for me.
A tip for use as well, put your feet on the flat bit (as shown in one of the photos) – it will hold it's position, but you can also easily rock your feet and ankles back and forward on it. This really helps to prevent fatigue of the muscles in that area.