FWIW, one have to realize that being an audiophile is often more than just wanting the same thing that professional musicians want.
Completely neutral, flat response is something that some audiophiles want, but some other audiophiles resent. Some people like purity, but others prefer to have some coloration that bring their music more to live than the way it is. It's a very subjective choice.
On a lower level, it's like the Sony V6, which is a pair of headphone that's been used for studio monitoring a whole lot of times. However, no one here will go out and glamour about V6 being an "audiophile" headphone, it is revealing and harsh, and only a recommendation because of its price, and at that price point you have to make a choice between having a revealing pair of headphone for detail versus something more smooth and musical.
On a higher level, you can consider the Grado HP-1 versus the RS-1, both are very much "audiophile" quality headphones; but HP-1 is known for its transparency and neutrality, and RS-1 is a more colored sound. A lot of people like the HP-1 for its neutrality, but a lot of people rather have RS-1 because HP-1 is just too neutral and sterile for their taste.
I have no doubt that UE-10 Pro is a very good pair of IEM for professional musician usage. The punchiness and the clarity of sound all speaks for its superiority for monitoring usage. The forward vocals and extra bit of extension in the bass region both help in such a situation. The extra microdynamics that 2X-S can produce might even be distracting.
However, from an audiophile point of view, both headphones are equally competent, just different. There's no particular advantage from either UE-10 Pro or 2X-S sonically other than a preference for a certain sound signature versus another.
There's more than one way to be an audiophile, otherwise we wouldn't be looking for tube amps to make our sound more organic. I wouldn't have the Emmeline HR-2 which gives me a colored, darker and warmer sound. If purity is the only concern, then everyone would get aiming to get a Grado HP-1 with Gilmore amps (or some other equivalent "transparent" set-ups).
I'm not saying this because I don't think that people should get the UE-10 Pro. UE-10 Pro is not the Sony V6.. it is quite musical and very enjoyable in its own sense. However, to dismiss other company's products simply because they're not a "professional musician's choice" is the wrong reason to dismiss a product. Professional musicians often has different ears and different taste than people who are on the receiving end of that sound, because of the work situation they deal with on a daily basis.
I also understand the mentality to not listen to an audiologist's advice as to what you should get. After all, audiologists are willing to sacrifice sound quality for hearing protection. However, also think about those musicians that plays with stage monitors blasting back at them, those who only wears IEM on one side of their ears, there's a lot of musicians who simply only cares about the best sound for themselves, and can really care less about hearing preservation.
I think we have seen our fair share of people on this forum who's complained about hearing loss, not being able to enjoy their music.. etc.. etc... So I personally do think that an audiologist's opinions are important, especially when the audiologist isn't just a hearing aid specialist, but a audiologist who specifically work with musicians.
I understand where Jerry Harvey is coming from, and the type of product he provides his musicians. However, I also understand where Michael Santucci is coming from, and the type of products he provides his musicians.