I use both and each has its advantages. Inflatables win in the comfort category, hands down. But when I need:

1) Small volume to fit inside my bivy or

2) A frame for my frameless pack that doubles as a sleeping pad or

3) Something dependable and bombproof that won't fail me in the middle of the night or

4) A litte extra insulation in Winter.

Then.....I reach for my trusty old Ridgerest or my cheapo Walmart blue foam pad. I'm lucky. At 52 my old bones can still sleep pretty well on a relatively thin closed cell foam pad.