I'm obviously biased being a hardcore NP myself, but I honestly don't know how to answer this question.
I've been more acquainted with NTPs than NTJs in my life.
I know I tend to feel more comfortable with Ps, in general.
Ne is such an open, expansive function, it seeks out new stimuli to store in its proverbial Ti/Si or Fi/Si bank, so I would surmise that ENTPs are the most open-minded of the the NTs.
Now, with NTJs, they've got Ni + Te, or Te+ Ni, plus the Fi, I think that INTJs tend to think they are always right, that they know better than all, or most, although the mature ones will quietly acquire new information that they previously did not know.
Ti, my my, Ti, what a linear labyrinth of a function, Ti + Ne, I dunno, Ti doms have a focus, or focuses, and they like to well, focus on what they care about, but I've found when you discuss new "outside" (to them) information with them, that they will gladly, if they find it interesting, soak it in, but, I dunno, what you tell them either needs to be simply factual, or in the case of when it's a theory in order for them to "accept" it, it needs to make sense to them, if something seems/sounds fishy to them, they will stop you in your tracks and lacerate whatever you're trying to tell them and illuminate all the holes that are missing to the theory.
One thing I know about Ti as a function is this...
Goddamn, is it THOROUGH, painstakingly so.
I have benefited a lot by being "trained" by Ti friends/teachers, I'm comfortable with gaps, they aren't, I'm comfortable with loose strings, I don't think they are, I could be wrong, though. :confused:
Now, regarding NTJs, I think that they can be INCREDIBLY open-minded when they've reached a level of intellectual and personal maturity where they understand that they do not know all, that others have insights and info to offer, that this doesn't threaten their intellect but rather facilitates it and fosters it to GROW.
I know a lovely ENTJ.
We talk about a lot of things, granted, objectively, like IQ-wise, I am significantly smarter than he is, not by a landslide but still, and he seems to have NO PROBLEM AT ALL with my intellect, my offerings of opinions, insights, ideas, he actually loves to hear them.
One of the better male listeners I've ever known.
But, he's special in that, despite the fact he is an ETJ, he is constantly yearning to learn new things, gain more experience, understand life better. He's lovely.
However, oy vey, he DOES NOT LIKE, rather, HE HATES when I give him advice regarding his non-existent love life.
At this point, I've just accepted it's a sore subject for him so I don't even bring it up anymore.
Actually, now that I think about it, NTJs don't respond well to advice, at least in my experience.
Is it an "I don't need you help thing?"
I dunno, it could also be a guy thing, but Js especially, just don't seem to like being in the position for having to be "mentored" or simply want or think they can figure out their problems themselves, I dunno.
NPs, or Ps, in general, however, respond pretty damn well to advice, eh, ITPs can be some stubborn ass mofos though, but all in all, I have found that NPs, NTPs included, seem to respond better to advice, I don't know if that correlates with open-mindedness, but it's certainly an observation I've noticed/experienced.