Thanks for sharing your experiences!

The only thing that sounds significant to me is the free choice of specialists. Can I throw money at it ad-hoc?

The rest of the benefits sound like they are more a convenience thing that can be solved by paying a one-time sum for the wanted benefit instead of the monthly premiums. Am I wrong?

I don't understand what's the benefit of funneling part of the money for a gym membership through the health insurer. I guess it's just a way for them to motivate you to stay healthy (go to the gym -> pay lower premiums)?