Another Stressless fan here but I recommend you try them out. Models have different shapes - not just sizes. Various models offer more or less support and have uniquely shaped seats and backs.
No question about this. I think the few who have expressed skepticism about Stressless chairs were simply not able to try a big enough variety of samples. That's probably why their dealership network is limited -- each one will have a number of display models you can sit in so you can get a good "feel" for them.
When DW and I went to look at them, we were both surprised that the ones we liked best were not what we would have chosen based on their descriptions. We lucked out, because there are only two dealers within 100 miles of me, and one of them is right in our neighborhood.