Used for the first time yesterday.  Took a few minutes to work out how to get them to fold up again so don't force it, take your time, once you get it then it's easy.  Really comfortable and stable.  We had intended to buy wooden ones but these came up as meeting all our requirements - fully folding, wheels, adjusts to several sitting positions and flat and at a fraction of the cost of wood.  Also a lot lighter so easy to move around.  Love it