Very comfortable, firm but not hard. It was funny when we started to open it as I just slit the polythene the air started to come out and the mattress started to expand.  Handy tool to slice the polythene provided with the mattress. It was so quick it shocked both my sister and I. It a great way of packagi9ng and make it a lot easier to get it to the bedroom. I have had it about a week now and really had really great nights sleep.