Do your mattresses perform differently on a solid slat base

We currently have a double sized sleigh bed frame with a pocket sprung mattress and a separate 3" memory foam topper. The bed frame has a solid slat base, which I understand from your advice should not need an mdf bridging layer.
We are considering a replacement mattress and wondered which mattress would you recommend between the Artisan Naturals and the Origins Pocket 1500? Would there be any noticeable difference between these two mattresses on a solid slat base?
Would there be any benefit in utilising the memory foam topper by placing this on top of the slats and placing the mattress on top?
I weigh 13st and my wife 9st