I can confirm that the fact that Hein is our NTs first choice 'keeper isn't saying much. For me, Okonkwo having seemingly overtaken him as Arsenal's 3rd choice doesn't look like a good sign. I don't watch much of the NT, because Arsenal already provide me with a dose and a half of shit football these days, so I can't really comment on his recent performances. From what I have seen before, I doubt he's going to make it as a top level 'keeper. He'll be a professional footballer for sure though, probably on a decent level as well, no need for such hyperbole.
I've watched one longer interview with Hein from about a year ago. He's really a level-headed guy with a seemingly excellent attitude. I wouldn't mind him proving me wrong at all. Considering he's just an infant when it comes to 'keepers, it's not out of the question.