I remember Concorde at Mach 2.02 at 60,000 MSL... now, THAT'S a cruise altitude! You can barely make out the Earth's curvature, and the sky is an inky indigo with a lot less "blend" to the demarcation between colors. I'll miss Concorde much more than those little Fokkers...

I also recall taking off with Piper Tri-Pacer from Truckee-Tahoe (5900 MSL) on a hot summer day... heading aloft to follow I-80 through the pass and dodge tunder-bumpers. Though it felt like I might have to taxi down to Auburn.

Power, weight and density altitude - interesting combo. WA B720 ex DEN or MEX - good power, real hot rods. AA 757 out of UIO, ditto.