It does help to hold the poses longer. I bought it as I felt I was so out of shape to do what the instructor does but I surprised myself. After a while the poses do get difficult to hold and I do use the block to assist. It is the right size and light weight. This is great as I am taking it with me when travelling. Looking for an inflatable one so it takes us less space. Shipping and delivery time was amazing.
They hold up pretty well until you get them warm then on the tall side if you are heavy person they will collapse and not be sturdy support. I will say they are the most comfortable blocks to sit on, but if you are heavy like me then go for wooden blocks.