>I just wondered if it would be worth the effort of hunting a good pair down?

Depends, but most likely not if you're planning on having them as a regular-use main headphone instead of an added splash of vintage flavor to add among a collection of several.

It's a vintage headphone with a vintage sound. ("What Harman target curve?") While not bad at all for its age and context, having first come out in the mid-seventies, it's still very much a product of its time and will be almost guaranteed to disappoint if one is expecting a modern full-bodied sounding headphone. And for more critical stuff like mixing, no. Just no.

The low end starts rolling off quite early and does so fast, and the top end is uneven and rolls off as well. When I had a pair for a while a few years ago (felt like getting a bit of nostalgia kick - my dad had pair when I very little), they initially seemed both rather bass-light and with an elevated treble, making for a rather harsh sound signature, but turned out it was mostly just the rolled-off bass. EQ'ing the bass up evened out things big time, but also highlighted the limitations of the old drivers, they can't handle that much bass boosting before starting to noticably distort at even slightly elevated volumes. Modern consumer grade headphone bass is very likely simply not a possibility with these. Comfort's OK, though the flat and thin, yet large pads feel a bit unusual - they're sized like they could easily be circumaural, but they're supra-aural anyway. They're also quite hard to drive, coming in 2000 and 600 ohm variations. Not like they need a nuclear reactor to get to decent listening levels, but a headphone amp is definitely recommended.

If you're dead set on wanting to get a pair, get them for the vintage experience with appropriate expectations, *not* to get something capable of going head-to-head with modern gear and comparing favorably. And shop around, don't overpay. Look for prices around for which you could get them sold onward without much of a loss in the case you don't wish to keep them.