Background
Traditional Metal coils
Typical older mattresses use metal coils tied together with wire to the coils next to them, so when one is compressed, the ones next to it also move. These are notorious for transferring motion on one side of the bed to the other, and not generally liked by couples that hate feeling every time their partner moves. The coils compress over time in the areas that have the most pressure and can sag in those areas. Typically the higher the coil count, the longer the bed will last the and more comfortable it will be. Different coils can be built to different pressure sensitivities though, so you have to find one that is soft or firm. The coils can be tied to the outside frame, and therefore cannot be used in an adjustable base that moves like an electronic hospital bed, something that is becoming more common post 2011.Pocketed/Individually sealed/Independent coils
One response to the annoying motion transfer of metal coils tied together is having the coils individually wrapped in a fabric. Because the coils are not tied together with wire and are not connected to the sides of the bed, they transfer less motion to the other side of the bed, and can be used on adjustable bases. Coil beds generally have a shorter lifespan than memory foam since the coils compress over time at generally a quicker rate than memory foam breaks down, but the beds can cost a few hundred dollars less. Coil beds do tend to have the same feel despite what the temperature of the room is, unlike memory foam.One salesman said that Simmons and Beautyrest had the best, or most experience with, pocketed coils
Polyurethane foam
This is an inexpensive foam found in sofa cushions and now beds. It may form body impressions within a year or two, but those can be comfortable for a while before breaking down, and have a lower cost. It doesn't transfer as much motion from one side of the bed to the other as the tied coils.I accidentally ended up with a 12" thick one of these beds off of Craigslist when it was wrongly listed at a Cloud Supreme Tempurpedic. I actually really like it. It has two densities of foam with a 4" low density layer on the top. It had body impressions after a year of use, but I find it comfortable.
Cons: If constant pressure is applied to a particular area over time, the foam will compress and not spring back as far or as firmly. This may end up being comfortable though, though probably shouldn't be used in a hotel where people may be picky about uniformity. It is not as good as memory foam as returning to the original position over time. The middle can sink in and two people can roll towards each other in the middle if it is low density foam.
Pros: I find it to be quite comfortable in my apartment with temperatures that range between 60 degrees to 80 degrees. The feel doesn't seem to change with the temperature fluctuation.
I tend to sleep more on one side of the bed than the other, as did the previous owner. While looking at the bed, it all looks flat, but the area my hips touch pushes down much more easily than other parts of the bed. Just constant use on that part of the bed made a body impression, which I find very comfortable. The other side of the bed is a more standard firmness and is fine, but it doesn't fit my body the way the worn way does. It is so thick and not very dense, so I can sleep on my side, back, or stomach, and I don't feel much and I sink into it so there is a constant light pressure on my entire body instead of only the parts that would normally touch something much more firm. It's a personal preference thing.
Memory foam
Memory foam is a foam that "remembers" its original rectangular shape and bounces back to that shape even after extended use. It breaks down slower than polyurethane foam, but you may pay a bit extra for it. It does not have the pressure points coil mattresses can and it also transfers less movementPros: Can be quite comfortable. Remembers the shape it is supposed to be, so it springs back to place longer than polyurethane foam.
Cons: Can initially get hard in cold temperatures, maybe about 60 degrees. Your body heat will have to warm it up before it sleeps at the firmness you are used to. Can get gooey at higher temperatures, maybe about 85 degrees.
Mattress covers
When you buy a mattress, there are durability warranties that say they will replace the mattress if there is a body impression more than a particular depth, maybe 1/4"-1/2". With the exception of TempurPedic, these warranties are void if there are any bodily fluids on the mattress due to bio-hazard. To prevent this, a waterproof mattress cover is recommended. Yes, these are plasticy and make the bed sleep warmer than it would without one, but this waterproof layer keeps dead skin cells from getting into your mattress, the food for unfriendly bugs. It also prevents blood sucking bed bugs from getting from your mattress to your skin.
There are fitted mattress protectors for about $40 on Amazon. They come in 12" think and 9" think versions. There are zippered ones for a little more. The ones made from pure plastic are the warmest and most noisy. The ones with a cotton terry cloth are less noisy and softer. The zippered ones are more of a hassle to get on or off, but prevent anything from getting in the entire mattress (except for when it is off to be washed). The fitted ones are easier to remove and have the primary barrier there, so they should be sufficient, especially if your bed is not brand new.
If you spent a lot on your mattress, and can deal with the way they feel under your sheets, you can put a full waterproof zippered cover on your mattress and then also put a fitted water resistant, and easily washable, fitted mattress protector on top of it.
You may also want to put a protector on your base to prevent it from collecting dust, especially if you have an allergy.
Adjustable Bases
Several manufacturers are now producing adjustable mattress bases to replace your stationary box spring. Many will let you recline, put your feet up, put you in a 'zero-gravity' position, and some will even vibrate. These are priced around $800-1,500.Be sure to check the warranty terms before buying. Some may cover motors that burn out for one year, and then have tiered repair plans after that, where you pay shipping, plus 10% of the value in year X, 20% of the value year Y... 80% of the value year Q. It seemed a little crazy for the ones I skimmed over, but they do feel quite comfortable.
Prices have dropped so they start at $600 on Amazon. The Queen Tempurpedic base is one option I got to use. While it raises hte dead and legs, has four presets you can create, and has vibrating motors in the center of the bed under your neck and feet. However, it does rattle if you shake the bed, which can be annoying... This is because it has rollers and the wheels can rock in the track. I would assume that adjustable bases without wheels inside tracks may make less noise if you move a lot.
Memory Foam Brands
According to one salesman, Tempurpedic makes its own memory foam. The rest of the manufacturers get their memory foam from two suppliers and put their own twist on it, such as amounts of blue gel for "sleeping cooler", something he claimed was all marketing, as well as making them in different densities.TempurPedic
This company puts a lot of money into advertising and has high consumer ratings.The viscous memory foam was developed for NASA and is heat sensitive. It becomes more firm in cold temperatures and pliable and mooshie when it is warm. Conceptually, the areas of your body that are closest to the mattress will be warmest, like your butt and shoulders, so the foam will become pliable there, but more supportive around your back which isn't being pushed into the foam as hard because less weight/heat from less skin contact is put on it.
The Pros: These beds, in my opinion are among the most comfortable at the 70 degree stores I have tried them out. My personal favorite is the Cloud Supreme, though it is 13 inches thick, so sheets made for beds 10 inches thick can pop off.
The Cons: If your room temperature fluctuates, the feel of the bed can drastically change. They are super expensive. Some people have commented that they sleep warm. That is why other brands started using blue cooling gels to separate themselves from this perception. One counter to this claim is that the more you sink into a mattress, the more material you have surrounding your body. Also, many people are recommended to purchase a waterproof mattress cover, and as far as they have come in terms of comfort, having plastic on top of a mattress does make the bed sleep a little warmer. So people switching from a coiled mattress with no cover to a memory foam mattress with a cover may start saying the bed is warm.
As of late 2012/early 2013, for a price premium, there are upgraded versions of the Rhapsody and Cloud Supreme with supposedly better ventilation for sleeping cooler.
I currently am sleeping on a 9" Tempurpedic Cloud with Tempurpedic Ergo adjustable base because I got a really good deal on it. Though moving the queen base up my three flights of stairs required disassembly from the metal frame from the base, so a lot of time. I don't sleep on my side much anymore with it because it is so firm, unlike my last 12" think very soft polyurithane mattress. While comfortable, I did have more back cracking on the soft mattress in the morning. I dis sink in up to three inches at my hips though. With the more firm mattress, I sleep on my back with a small towel or a gel neck pillow. I often wake up sprawled out on my stomach though.I haven't had it long though.
