When we bought our bottom freezer fridge, my husband wasn't sold on the idea at first. I asked him where you spend most of your time looking, in the fridge or the freezer. When the salesman came back to help us, DH told him we would take the bottom freezer one. He hasn't regretted it. Now he is looking at the side by side for the water dispenser aspect.
As for a mattress, you both need to try them out. It's personal preference.