You will be shocked at how great a night's sleep you will get.
We get great feedback on our mattresses. They are a thick high-density foam that is both forgiving and supportive. We are positive it will be the best sleep you've ever had while camping.
If you are the 'princess and the pea' type, there are some options. If you have a Sparrow tent, you can add a 2-inch memory foam topper on top of the stock mattress and still be able to close up the tent.
If you have the Condor, or don't want to go the memory foam route in your Sparrow, you can pick up one of the Exped Megamats. This is an inflatable mattress that would replace the stock mattress. One extra benefit is that you can deflate it when closing up your Condor and free up some extra space to store some bedding when you wouldn't otherwise be able to!