I have a mix for versatility and to avoid the issue of memory foam getting cold (have yet to experience this but have read about it).
I have 2x Teton sports sleeping pads, which side by side fit perfectly between the wheel wells in my truck bed (i have a sleeping platform back there which is carpeted). I chose these for their portability since i can roll them up and carry with me if i want to hike and camp outside somewhere or want the pad to lay down on, etc. Yeah they are not the best choice for backpacking because of weight but most of my use is with them in the back of the truck so they work for my needs well. I also purchased a 2" gel infused memory foam topper and cut it to fit the size of my sleeping platform in the back.
My plan is for camping in warm temps, i put the memory foam on top of the Teton sports pads so a super comfy bed, and if its cold and the memory foam turns to rock i can just put the Teton pads on top of the memory foam topper. I have yet to test this out in the field with cold temps (works great right now in summer temps, very comfy bed), but i don't really plan on doing much camping in freezing temps.
Gel memory foam topper -
https://www.amazon.com/gp/product/B019J9AUZW/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Teton sports pads -
https://www.amazon.com/gp/product/B00GV3YSV2/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
Personally i think the teton pads are way overpriced since you get **** foam but it was the only camping pad i could find in the size i wanted. If you can sew up a cover like this with the compression straps and handle you can probably make one much cheaper and get nicer foam for the inside. I have also considered chopping up my memory foam topper to fit inside the Teton sports covers and replace the foam inside them but then i have to worry about the cold temps issue so that idea is on the back burner until more research.