If you use a lower R value pad for 85% of your trips, it's way easier/cheaper ot add a $40-50 closed cell pad to that to get to your 5-6 r value for snow compared to buying a whole separate pad that is 5.5+ R value for something you don't use as frequently. Also - the closed cell makes a fantastic big sit pad for eating/resting/etc when on snow to give some insulation and waterproofing when cooking/eating/relaxing outside the tent. I bring a short length closed cell pad on even my summer trips to use more as a big sit pad than insulation at night just because it's comfy to have a little cush to sit on and keep myself out of the dirt in camp each night. | 
