I’ve got a Numo and other self inflating Alpkit mats -all good bits of kit.
The Numo is an inflating mat and has the following advantages and disadvantages compared to a self inflating mat:
Positives – It packs down smaller and is lighter than a self inflating mat of the same size and thickness.
Negatives – It’s not as warm (ie has a lesser r rating and therefore doesn’t insulate form the ground as well), it won’t fit inside smaller bivi bags therefore you need to consider using a groundsheet if using on rocky ground (some people use thin packing foam which also increases the r rating) and (a minor point) it takes longer to inflate.
I tend to use the self inflating mats for car camping and the Numo for Spring, Summer and Autumn bivi’s and lightweight camping. For winter bivi’s I pinch my daughter’s alpkit “little kippa” self inflating mat combined with a bit of old karrimat.
Al – I agree bigger mats are more comfortable but you do get used to having a smaller mat and not moving about as much; all depends on where you’re prepared to compromise in terms of weight / comfort / cost.