I don't know if he's an instant star but Penix fits that description in terms of ability to throw any pass with a lightning quick release. I know you're not a fan of Penix, but watch some draft profile reviews of him on Youtube and you can see it.
Among the other top prospects all of them have good arms. None of them really stand out for their arms besides Penix, though. Williams is good at avoiding pressure and going off script. Daniels is electrifying as a runner. Maye is willing to make difficult throws. Nix is great under pressure. McCarthy has the leadership skills you want in a QB who has to have the confidence of his teammates.
Of this group of QB prospects, however, Penix is the guy who's going to rip off the 50 yard, hit-the-receiver-in-stride-down-the-sideline-throw-as-the-defense-is-about-to-get-to-him-with-the-blitz pass. He routinely did just that at Washington and in fact I've heard him criticized for doing it as some reviewers think he just finds single deep coverage and chucks it under pressure. Still, he finds the favorable matchup quickly and does try to hurt the defense for gambling, and it worked a lot of the time because he throws with such velocity and accuracy that his deep receiver usually had a very good chance to make the play. Penix gets criticized a lot for his footwork as well because he'll often throw without setting his feet and some feel it affects his accuracy. I'm not as sold on that. I think the guy is talented enough to play see-it, throw-it. In the split seconds another QB would have to flip his hips and set his feet to have a chance of altering where he wants to throw it, Penix has the ball out and very often on target there. Split seconds add up over the course of a game and are often the difference between an open and closed passing window. With Penix, if the window is open and he sees it he can exploit that opportunity. Consistently.
Not saying the other prospects are terrible at any of this. They often handle similar situations slightly differently or were asked to do other things that didn't put them in as many situations. But if you're looking for a QB who can make a defense pay with his arm, out of this group of prospects I'd put Penix at the top.