I have a wood floor in my front room, where I spend the majority of my time with my 6 month old son. He sits up fairly well but has the occassional fall and I was looking for a soft mat where he could sit/lie/move safely. This mat is soft and fairly thick but I still use a nursing pillow to surround my son for when he falls from sitting and bangs his head; I felt the mat wasn't quite thick enough by itself. However as he gets more confident sitting and falls less I'm using the pillow less and less.
You have to be careful when standing on the mat if it is on a wood floor, as it can be quite slippy.
Good quality, easy to wash and good value for money at the reduced price.