Check with retailers in your area to find out what brands they offer. Each retailer will likely have set deals with certain mattress manufacturers to stock their brands in the store, so check several different retail locations. Since relationships between retailers and brands can lead to salesperson bias, ask for literature on brands so that you can take the information home and compare different brands to each other.
Learn more about the mattress brands that are available in your area by checking with third party organizations that rate mattresses, such as Consumer Reports or The Better Sleep Council. These are nonbiased organizations that can give you another opinion on what each brand has to offer. You should also look into how long each brand has been in business, and how consistent their products have been over that time.
Consider the pros and cons of the mattress you are replacing. If the size and firmness have been consistently comfortable, it's probably not a good idea to risk a major change. However, make sure you are thinking about the mattress in its prime condition, and not during the last months when you realized that it needed replaced.
Incorporate multiple pieces of information into your decision. For example, just knowing the a mattress has the highest spring count does not mean that it's the best mattress. While it may have a lot of springs, another mattress with fewer springs may have thicker springs that actually lead to more comfort. The quality of the upholstery can also play a big role when it comes to comfort, especially when a brand is offering a pillow-top mattress.
Lay down on the mattresses you’re considering. This will help you figure out which firmness level you and the person who might be sharing the mattress prefer. Again, if you’re happy with your current mattress firmness, go with that. If not, test out some other options. Be sure to lay on the mattress in your regular sleeping position with your partner if you’ll be sharing it.
Talk to a doctor if you have health issues that impact the way you sleep. Since you can't spend an entire night sleeping on a mattress you're considering, it's possible to make a wrong decision, such as choosing a soft mattress that feels comfortable at the time but may hurt you back hours later.
Factor in the price of the mattress. While comfort is a major concern when comparing mattress brands, you should also consider price. A of 2011, a new mattress is generally an investment of at least several hundred dollars, but prices can be as high $1,000 to $2,000.
Choose a warranty that offers more than just a replacement mattress within a certain number of years. Replacing a faulty mattress is important but it's the small adjustments to the mattress that may impact the way you sleep. For example, a manufacturer that can come and fix a spring that is poking out or replace torn upholstery can save you the hassle of trying to prove that the entire mattress needs to be replaced.