I'm on the same boat, except I did 5 successful / profitable years rather than your 20!!!
I was sitting there in a big bank who was offering me a nice permie package... why the hell not? They are a great bunch and I am thoroughly enjoying the work.
Yes off course I will miss all the Contractor perks, but at the same time I am already enjoying the perks of permiedom (eg no slight uneasiness in the gut re contracts) and all the benefits that come with permiedom with a good company (medical cover, life insurance and a boat load of other benefits I didn't know I needed or existed!).
Contracting is still a perfect fit for some people, but I agree that the "contracting vs permie" divide is getting closer.