I'm aware a lot of pilots - especially those of the old school - tend to have a lot of love for Douglas, but from an engineering perspective their designs erred towards the conservative, even by 1958 standards.
Not to be argumentative, but from a pilot's standpoint the rock solid DC-8 has no airframe life restriction, it will fly without hydraulics (automatic manual reversion), and from a science platform standpoint it will fly 12.5 hours with ~4.0 hours of that being at 1500' AGL/MSL, plus reserves. It will also slow to low speed buffet at optimum altitude or above and then accelerate back to M.80 (sometimes a science requirement).
What also might be interesting for some who don't know about the DC-8, it will dump fuel without electrics, as long as there is gravity, that is.
From a freighter standpoint the -73 delivers what the 707 could only promise. BTW...fly through weather nasty enough to block the pitot tubes? The autopilot doesn't trip off. Only zero airspeed indication for awhile. If anything, the Achilles' heel is that it has no wheelwell fire detection.
Frankly, from an engineering and performance perspective, with four-engine redundancy, there is no better science platform, particularly for surveying the ice low level over Antarctica four plus hours from the nearest airport in South America with 35 scientists and crew onboard. Not bad for a 1958 design. Of course, I'm an admittedly biased pilot who greatly appreciates what the airplane provides and not an engineer. Its an airplane that asks you to be a pilot and gives honest, real-time feedback about your attempts toward that end. Maybe that's what I appreciate about the old-school machine. And remember that it did go supersonic without any structural issues realized. From a pilot's standpoint, all of the above is the kind of conservative, common sense engineering I like.
Apologies for the off-topic, but aircraft robustness and capability is somewhat relevant to the discussion.