That is certainly true, Pace. My first instructor used to say of the C150: "nothing to do and all the time in the world to do it" ! It didn't seem like that to me at the time, though.
One thing I've found fascinating is the saturation effect on the brain. When things start piling up, pilot performance can drop very rapidly indeed. I had a friend who owned a very nice early model C172 and, in my estimate, flew it pretty well. He sold it and bought a PA24-260 (Single Comanche) and, despite the efforts of his friends and instructors, he was never able to cope with the faster aeroplane. Perhaps if he'd been 20 instead of 40, and had more practice and different instruction, it might have worked out differently. But it seemed to me (in the right seat) as though he was having both input bandwidth and processing speed issues.
I've not flown jets but I understand your joy in returning to slow flight. I enjoy flying whatever is around but these days 100 kts in my VLA with the panoramic view is about right for a Sunday afternoon.