I finally got bored enough that I decided to spend some time boning up on coil springs / innerspring mattresses.

Time to learn about Bonnell springs, coil counts, wire gauge, and whatever else is important in the world of innerspring mattresses...

How did you get that link into your post??? I tried!  I notice L&P has a new coil called Verti-Coil. I wonder how that is compared to the LuraFlex. I love researching this kind of stuff!

"Remember: Once you're asleep, every mattress feels the same."

LOL!   This thread is a good short primer. 

Here's another guide and it also discusses foundations a little:  http://extension.usu.edu/files/publications/factsheet/HI_08.pdf

Here's another, more global, perspective:    http://www.mattressinside.com/orthopedic.html