Had our zen hybrid for about 6 weeks... and we love it, to the point that neither of us are comfortable sleeping on another mattress. Case in point, about 2 weeks ago, we went out of town and stayed with a family member. They had a newer mattress - less than a year old - that they allowed us to use. I woke up with pain in between my shoulder blades, and my wife (who is pregnant) said she couldn't find a comfortable position to sleep in all night. We came back after a few days - and after our first night back on our Wave, all pain gone, back to a deep and restful sleep.