When I first got this mattress it was amazingly comfy and I slept well. However, three years later and I wake up with minor back pain. I have discovered the mattress has started to sag a little towards the center and that it's not holding its firmness as long when laying on it. For reference I am using one of Zinus's bed frames so the mattress is fully supported and therefore what it is resting on is not the cause. I don't do anything special with the bed, only sleep so it's not getting extra beatings or damage. Knowing Zinus offers a 10 year warranty for their mattresses I contacted them with all the information they required to make a warranty claim. This included photos of the mattress tag, screenshot of proof of purchase, photos of the mattress with a rod/broomstick laid across to show any sag, a side view of the mattress with a ruler showing it it has lost any form or height, and any other images to help show proof that the mattress is defective. I did all of that. Every single thing on the list and even added placing a level on the mattress to show that the air bubble moved away from its center to indicate there is a slant. The not so professional customer service got back to me with a decline on my claim stating I needed to show proof and that the images did not show any problems or significant proof. I would have been fine with a simple "your mattress does not show enough of a sag to meet the minimum requirements of our warrant (I know how strict companies are with making sure the item has specific requirements for warranties). However, that was not what I got. I instead got instructs telling me to send them photos of all the listed above items and to explain the defects all over again. They want me to do circle logic and jump through hoops to tell me my mattress doesn't mee the minimum requirements of their warranty. So, I'm being insulted because they say they looked at my photos yet by telling me I need photos for proof (which I already provided) they didn't actually do their job and look at my proof. This is a shady company that will do anything to say no to their promises and I don't ever recommend buying any of their products. They don't live up their their 10 year promise and warranty and when they do break they don't honor anything. Instead they request their customers go through circle logic and jump through hoops. It's bad business and they won't be getting anymore of mine.