The T&N mattress is great. I've been having the best sleep for days now. I'm over 200 lbs. and I purchased another bed for my mother who is around 110 lbs. We both describe the bed being perfect with not waking up with any pain. My only reason for not giving this a 10 score, the support around the edges are a bit soft. If you sit on your bed to dress or tie your shoes, you may not like the sinking part. While in bed is GREAT.
I replaced a 76" x 80" king with two of your 39" x 80" extra long twins on two Leggett and Platt adjustable frames. I did this knowingly that the Bed would be 2 inches wider been combined. They sit inside a sleigh bed fairly well. The fear for the mattress is excellent and since both my wife's and my comfort level. I knew the measurements when I selected the beds.