Princess and the pea type difficulty

Thank you Mike for your answer of 5th of May https://johnryanbydesign.co.uk/understanding-beds/question/hybrid-foam-mattress-smell-similar-memory-foam/
Now I have spent so much time trying mattresses I am no longer sure what I need, but I know I had a JL Ultimate, medium in 2000 that was the best mattress ever and only got soft after 9 or 10 years so I did have to replace it. Since then I have not been able to find a good mattress and the Ultimate is basically so unaffordable (between £ 2,600 to 8,000).
So I am asking whether your natural fibre spring mattresses such the Artisan are able to conceal the feel of the springs, this I found is the main problem I currently have with many spring mattresses I tried, I am looking at medium firm, since my husband and I are between 84 and 86 kg, he is slightly heavier, and we only have a double bed, he has back problems, and I have a controlled generalised inflammatory arthritis, it has to be comfortable but not too soft not too hard. I know it is not an easy question to answer but I have read a review that says the padding rapidly felt flat in an Artisan Luxury in soft tension, although this review is from 2014. So I wonder if you could advise what would be the strategy to avoid this since we are both heavy sleepers.
Thank you