Number one, the customer service at Ghostbed is excellent. There was a timing issue involved and the folks at Ghostbed resolved it fairly, definitively and amazingly quickly. Very happy there. Now, the Flex:After sleeping on the Flex for about 3 weeks, I have to give it a 5. It’s not a 4. The Flex is an honest, well made bed. A solid, firm, comfortable bed as advertised. When you first get on (I waited about 10 hours), the bed is quite firm, but comfortable. After a few days it softens up a bit, But not too much.I say not too much for a reason. I had the time to test out a couple of other more expensive hybrids. One was like sleeping on a cloud--very comfortable to test. The other was like sleeping on a trampoline--forget it.The first night I slept on the Flex, when I first laid down, it felt firm. I have chronic lower back and shoulder pain. Old injuries, annoying. After a short while I realized my back muscles were unknotting and relaxing, because, unlike a super soft bed, the Flex technology gave them the support required to relax. It feels great once you get used to it, which happens quickly. The kicker is that when I woke up in the morning and got out of bed I suddenly realized my back didn’t hurt for the fist time since whenever! Wow! I'm not kidding. And it continues improving my spinal situation. If you a have a back problem, even if it's muscular, or scoliosis, you need a firm bed. Sleeping on a cloud is nice, but won’t really help. (Cloud is not in the product’s name, btw.) It’ll feel luxurious at first, but will sink over time. Without tensile support, the sag would probably make your back worse over time, not better. You need enough support. Also, it’s quite cool, temperature-wise. And my wife loves the way it looks. This is a great bed for anyone that wants to promote spinal health in a solid no BS high functioning hybrid bed and get a good night's sleep. This is not a cloud. it’s a really good, supportive bed.