manrow
I really have to agree with Huck on this one. If you don't practice, you won't be very good.
You indicate the superiority of the autopilot at altitude. I really wonder how well you would do at max op alt, with the autopilot off or out of service.
Maybe you would descend. Maybe you would be all over the sky. Or maybe you might hand fly to altitude, trim, set power/thrust and let go for a few seconds before engaging "george".
But as Huck said, the horse has been beaten to death before.