ASFKAP,
Very valid point. I do not know why nobody picked up on the flying tailplane. DLC probably does not make sense in the day and age of Flap 3 landings on Airbus, although the A318 has partial spoiler deployment for steep approaches.
There are other features though which found their way into other successful programs. FMS is one of them and was introduced on the L1011-200 with Saudia I think and many -500 customers used them. It paved the way for what most of us Airbus drivers take for granted like optimum climb, cruise, descent speeds, optimum cruise flight levels and much more.
Also the Airbus soft cruise looks very similar to that of the -500.
The -500 was the first aircraft in which you could hold a optimum cruise Mach number with the use of FMS and Autothrottle. Small Mach variations are corrected by pitch commands letting the cruise altitude vary by +- 50 ft, whereas larger variations are corrected by smooth throttle adjustments. Looks very similar to our A320 ALTCRZ doesn't it.