I wouldn't have thought 9 minutes till supersonic is anything to shout about
Erm, that wasn't just supersonic, it was 9 minutes to
Mach 2. I would suggest that the ability to do that without bonedomes, bangseats or spaceman suits - and with room for 100 punters in the back - is pretty impressive.
From a engineering point of view, I'd say it was the most impressive aircraft ever built.