So far we have unboxed it and it's already almost to its full size. Its built so you really don't need sheets with it, but we bought the Serta cooling sheets along with this so we will have extra cooling all the way around. So far, from just laying on it for a brief few moments. It's like laying on a cool compress, and with this being the hottest part of Texas heat it feels amazing. If you are wanting a cooling bed definitely buy this one it is so far amazing!

My sons old mattress was hard and it was also dipping in the middle. Its only been a day, but my son is so much happier with his new mattress.

I was initially skeptical of purchasing a Serta mattress in a box, but internet reviews seemed to indicate a quality product. The unpacking process was straightforward, and the product expanded within a few minutes. The first night was amazing compared to our old mattress. I was happy that the cool-feel cover retained just the right amount of heat. I would recommend this product.

I had my first nights sleep on the new mattress and am very pleased. Even though my prior mattress had a deeper depth, I didn't sleep well on it.

We had many friends spending ridiculous amounts of money on memory foam mattress. We liked our traditional Serta so much we decided to look at those first. After trying a lot of foam mattresses we bought another Serta. The quality seemed too similar to the higher priced versions for the difference in price. We expect just as many years of comfortable sleep on the new one.

We bought the Allerton twin set for when our grand child visits. Couldn't beat the price for a brand name product. Nice and firm. It should last many years.

Wife and I love this matress. Finally a mattress that is comfortable all night, we wake up feeling rested. It doesn't get hot at night. Well made material. Had trouble sleeping but this bed has fixed that it's so comfortable you dont even wanna get out of bed. Highly recommended.

Was very impressed by how comfortable this mattress was. It really makes you look forward to going to sleep.

This mattress is by far the best one I've had. It's comfortable even for a firm. It's not like the other firms that are as hard as a rock. Would definitely recommend this for everyone! Thank you for helping me get a good night's sleep!

I’ve been wanting a new mattress for a while now and I must say my choice in getting this serta king size firm mattress was the best choice I could have made.

This mattress has to be the best mattress I have ever slept on....bar none. I was cool all night...no sweating at all. The size of the king mattress fits all my standard king sheets nice and snug and doesn't move at all throughout the night. Easy to clean...just spot clean with a wet towel and some soap. I recommend a light mattress pad or cover to protect the mattress from stains. Very comfortable and doesn't create pressure points while I sleep so that when I wake up, I am refreshed and not still tired.

Serta has the Stay listed as right between soft and firm on their scale but I'd say it leans towards the softer side, it's the type of mattress where you instantly sink and it molds to your body but it still feels very supportive through the night. I feel like mattresses are definitely personal preference, what's too hard or too soft for one person might be perfect for another but for me this was just about perfect. It's soft yet supportive and I don't have any of hip pain and leg numbness I experience with firm mattresses. Other than comfort, there were two things that stood out about the Stay to me, the first being the 4 layers of foam. The top layers give it that cushy sink in softness and the lower layers keep it supportive. If you press down hard enough especially at the edges you can feel the change in firmness. The second was the cover, it's soft and cottony and here's the big plus, it unzips all the way around (there's about an inch that does not unzip). I haven't tried it yet but it seems like it will remove completely for washing and underneath the mattress is covered with a cottony blue fabric. I have a 3-year-old and accidents happen so I'm probably overly excited that it seems to be removable and washable. It's a simple thing but it's a game changer and I can't believe all mattresses aren't made this way! Set up is fast and easy. The king box is roughly 21"x21"x46" and shipping weight showed 127 lbs, small enough to fit easily in a trunk and while heavy I was able to drag it in and set it up alone. Definitely get it on the platform or box spring before opening. It expands quickly and will be the full 12" within minutes. There is a minimal smell from the memory foam which I expected, it dissipates pretty quickly but I did open a window for a few hours to help air it out.

My first pillow too Serta was awful, I only had it three years an within that time one size had sank. But this foam mattress Serta I purchased it sleep like your on water that’s how amazing it. Wish I had purchase this three years ago

I have bought several mattresses over the years for myself and my children. This mattress is by far the best. It is soft and comfortable. It is easy to get out of the box. Take the cover plastic off and it puffs right up. I slept so well the first night using the mattress. It is not stiff or too soft. Perfect height for me. Very pleased. And will be making more purchases for my children.

I love this gel memory foam mattress! I like that it came in a box and as soon as I took it out it easily unfolded and I placed it on top of my bed box spring. The gel memory foam makes the mattress feel so soft, firm, and comfortable. It also provides a cooling effect which makes it much easier for me to sleep at night. Since having this mattress, I have slept great every night.

I’m so amazed by the quality of this mattress. I don’t think I’ve had a better nights sleep than I have with this bed. First of all, unpacking it wasn’t too difficult, although it did take some time to fully unfold. But once it was done, it was immediately ready to use! It’s such a comfy bed, and sleeping was so easy! I definitely recommend this mattress.

I can't say enough good things about this bed!!! I admit I was skeptical at getting a mattress that was delivered in a box, but I am so glad that I did get it! It is hands down the most comfortable mattress I have had. It is so nice not having to worry about springs or creaks when you are moving around. The mattress is great for all types of sleepers as well. I love to sleep on my back, but I can never seem to get comfortable in doing so,. This bed lets me sleep on my back and I wake without any back pain. The mattress conforms to all my curves and hugs everything just right. I also can move around without feeling like I am disturbing my partner and he sleeps just as well as I do as a side sleeper. I would definitely recommend this mattress and will be purchasing another one in the future.

my sleep has improve am very happy with this mattress

I like how lightweight the mattress and the box spring are. The mattress has got a good bounce to it, while also being quite soft to lie down on. I've had it for two nights, and I feel well supported and comfortable. Also, the prices cannot be beat! A little over $400 for both the box spring and mattress! I feel very happy with the value and quality I got. Thank you Big Lots and Serta Mattresses!

This is the most comfortable mattress on the market for the price, it's unbeatable. I looked at tons of mattresses and even the ones for twice or three times the cost weren't as comfortable as the Serta Stay. Call around to your local Big Lots for availability, go check one out. You can even take it home in a box the same day and sleep on it that night! You will be so glad you bought it!