We were going through the same tough decisions when trying to find a new mattress set. We couldn't decide between a memory foam, air, coil, etc. I have a really really bad back and it makes finding a mattress even more difficult in knowing you made the right choice. I found a effect bed for us and we absolutely LOVE it. It is a hybrid mattress with a coil bottom 2/3 of the mattress with foam and cooling gel making up the rest . It is a Serta icomfort series hybrid. They have a few different models with different levels of firmness to meet your needs. I chose it because the high individually wrapped coil count gave me the support I desperately need to keep my back aligned. The foam gave the cushion and eliminates the soreness at my pressure points (hip, shoulder, knees etc ) while the cooling gel keeps us cool at night. It is a perfect compromise. They also have a 60 night in home guarantee so if you don't like it after sleeping in it, you can return it .
Sorry to sound like a salesman! I really don't sell them nor do I have any affiliation with them. I am just a person who trialled 5 different mattresses in home and returned each and every one of them until I found this one. The king set including box springs, frame, and mattress protector was just under $2500 I believe. I hope this helps!