I compared the Camped 3.5 to the considerably more expensive Exped SIM 10 Comfort mattress. I preferred the Campbed because there is no tendency to roll off its edges, whereas this is a problem with the SIM. Also, the fabric of the Campbed feels softer against bare skin.
I also compared the Campbed 3.5 to the Exped Synmat 7, which is about the most comfortable backpacking mattress you can buy. The Campbed is noticeably more comfortable, but also a lot heavier and bulkier.
As a kayak camper I normally use the Synmat 7. But if I'm only going a short distance I strap the Campbed to the rear deck because it really is more comfortable.
I'm giving the Campbed 3.5, size regular, a 10 for its category. Understand that there are many car camping mattresses that are more comfortable, but that's a different class.