About 6 months ago we got a bedinabox.com mattress. It is heaven!!! It is made in the USA, was awesome delivery, came in a box, easy to take upstairs and was ready to use within hours. We just got the basic queen mattress as we read reviews of people putting "pillow topppers" on foam mattresses and you loose the whole effect. It does get warmer than a regular spring mattress, but both of our bodies adjusted perfectly in about a week.
Definitely do you research and try some out. I understand that they aren't for everyone as yes they do seem hard but there are different levels of foam/hardness.
Also bedinabox has an awesome 30 day return policy... Memory Foam Mattress | Memory Foam Mattresses | Memory Foam Reviews | BedInABox.com - Return Policy
Anyone would think I works for these people haha, but I don't! I just love the bed. And the best thing? The prices!!!! I think we paid just under $500 for the queen. I think it has gone up in price a little since we bought ours on sale.