The absolutely relevant key aspect about Hugh Herr is that a brilliant inventor and at the same time very demanding user can iterate the development cycles very fast and very well, whereas other projects not even make it to taking actual / real users into the close loop of development.
It is an irreplaceable key requirement for good prosthetic arm / hand engineering to work extremely closely and directly also with their high performance users. That, as even the 3D printing community has found out now, is a sine qua non.
There is no way around it. Any other process will invariably result in deteriorated developments, in products that by design fail the market.
Any flaws in that design process show extremely rapidly though and usually, trying to sell failed design type products anyway will be tantamount to the famous "riding a dead horse" metaphor. These products, today, are a reality. We can of course go deeper and see where and how these days "dead horses" are ridden within the community that is forced together by fate, that is, amputees (that did not chose their fate), prosthetic technicians (that did not chose amputees to be real living hard working persons), prosthetic component manufacturers (that have a valid urge to build cheap stuff, sell it for a lot more and be loved for it), academic researchers (that stack wrong premises on top of each other and then wonder why their output stays academic) and the public (that spends a lot of tax money on, well, prosthetic technicians, component manufacturers and research and then wonders where the results for real life amputees are).
If you want to get a better product you want all flaws exposed (so the user needs to find all flaws fast and characterize them well) and communicated, then received and improved on (so if the engineers are narcissists the development stalls). The importance of both aspects is very high.
I have written evidence of big large companies, component manufacturers, that act out their narcissism even when I just confronted them with "cheap manufacturing / absent quality control" (which is an easy thing to identify, not much characterization skill required) or "deadstock wares" (stuff that died by itself, unused) - so you can basically figure out yourself just how much problem insight and engineering improvement one can expect there on a more sophisticated level (nothing really). If you ever want to know where your company is at with regard to this just find a design mistake they did (also mailing that as an amputee, a person with a disfiguring disabilty), point it out to them, and see how they react. They usually forget that an amputee is just that and many things other than that; so their sentences to explain the unspeakable ("how could an arm amputee ever have found out that we have very cheap business practices") usually contain a "BUT" clause (such as "he is an amputee BUT found a way to measure exactly") which then tells you how stereotypically simple their world views usually are.
So I was not surprised to hear an iLimb question I had asked already a few times ("can grip switches be made a lot easier") answered with "we are introducing more features and gadgets", when instead they could have answered very simply ("no"). So a new approach to switching grips on a future iLimb model is wearing an Apple Watch, having an iPhone (already two devices we knew did not work too well but cost too much) to quite possibly use the iPhone's bluetooth connection to control the iLimb (and we know just how reliable these are).
So companies find the common ground between "what is exciting and creates a tickle of novelty" and "what is cheap to build" and that, as we know, is not exactly "what is better" (because god placed deep thinking before good engineering).
But then it is a fascinating scene that unfolds and develops, much like one cannot take the eyes off a sinking ship.
Also, his very functional prosthetic feet and ankles in a way match the extremely versatile approaches of the prosthetic hook. For very interesting and totally irrational reasons though, "society" does not see a prosthetic hook as what it is in relation to usage, work, manipulation (i.e., people, manufacturers and researchers are unable to actually take the blue collar perspective on this, which would cause research in prosthetic arms to go all functional) but what it is in relation to anthropomorphism, representation, appearance instead (i.e., they take the view that a hand that looks like a hand is better than anything that actually functions) and interestingly, this does appear like a white collar, aristocratic or otherwise feudal barbarian view - but even there, the leisure class (basically comprising all that are too lazy to actually provide hard physical work) takes reference with the high priest class; there, Catholic church always banned the physically disabled probably because they found that disfigured / disabled people were not the right types of projective surfaces.
So if you want to play at the level of the symbol driven white collar work-shy leisure class, wearing a puppet type hand, you will eventually and very slowly (just because in that class people never speak their mind) find out that they discriminate against handicapped people even more.
At that point your "bionic" hand has not gone anywhere functionally and you are left with a whole pile of social, orthopedic and other issues and the best thing you can do *then* is stick to your true friends, get a prosthetic hook, do a lot of sports and call it a day.
It is a real pity Hugh Herr did not develop prosthetic hands too though.