The SR-71 was so far ahead of its time, it's a little ridiculous. Look down/shoot down capability in the mid 1960s. Synthetic aperture radar mapping. An IMU/astronavigation system almost as capable as the early GPS units of a few decades later. An airframe that actually becomes stronger the more you fly it as designed. Thermal management system techniques that weren't used elsewhere for decades. I can keep going. But basically, for almost every single system in the aircraft, the next comparable system you can find was developed at least 1 to 2 decades later.

Oh, without a doubt. ARM assembly is a joy to code, much more so than any other. It just feels... right. There's no fluff and cruft and, at the same time, it didn't feel like there was anything really missing. RISC processors have a reputation for poor code density, but the ARM, even when it came out originally, was the exception to that rule: it was pretty easy to get code density for the ARM comparable to that of the 680x0 and x86.

It's a wonderful achievement.