In reply to Gob_Stopper:
after a few years of various inflatable mats, including a number of alpkit's, I now stick with my ridgerest.
even the most durable and reliable of air mats wont be as durable or reliable as a foam mat.
it can be very nice to have the extra comfort, but I've often found in the morning my back is worse off for having been on a inflatable mat.
for what it is, the numo is an excellent mat at an excellent price, but if you're getting on fine with you're ridgerest, I'd stick with it.