Interesting discussion.
As PIC, most of my time airborne has been 1000 AGL or below, I don't have a FW rating. On a ferry flight from the Robinson factory I spent a short time above 4,000 AGL from Northern Ca. into Oregon, what I found most notable was the loss of the sensation of speed that I was so accustomed to. The feeling of standing stationary on the edge of a building took some getting used to. I've been on a few solo X-country flights in a C172 and did not have the same sensation, possibly because of the limited view. I feel compelled to go upstairs and check things out again.
Mike