I had seriously considered Exclusive Resorts around 2003-2004, but we ended up purchasing our own vacation home instead (one can question the sanity of either choice in hindsight!).

This is the first I've heard of Inspirato (was aware of Portico) and I do think AmEx could really add value to Centurion by offering membership in Inspirato with fully waived initiation fees to Cents. If the annual fee only covers the ability to use the site and get 'discounts' then this should also be waived or substantially reduced for Cents ($2600 annual fee sounds extreme), particularly if AmEx is then going to offer discounts on membership and annual fees to Platinums.

No flyer for me yet but I don't travel as much as most here, and my air travel this past year was either on miles or paid by work, and I only had a couple of hotel stays charged to Cent.