It really baffled me how some started lamenting over what a quality screen setter Ayton was early this past off-season. He did set a lot but they'd often lead to the ball handler being doubled because he wasn't a credible or reliable popper or roller. Like you said, he'd often slip early also and that didn't help matters. I think the best screen setter in the league is Steven Adams, not because he's a threat to shoot or anything but the guy is a brickhouse that stood firm and would have defenders literally bounce off of him. Nurkic is much closer to Adams than Ayton. He had that quote before the season also, "I give the defender one option on my screens, to go under." and that's what I've seen in game. He's good at rolling to the basket and a decent pop threat also, although I'd like to see his outside shooting improve.
The best thing about Nurkic is you don't question his measurements. He's listed as a 7' 280 pound Center and he looks and plays like that, every possession. Ayton never appeared like a legit 7' footer and never used his supposed 250 pounds to his advantage.
Found the piece with his quote, added a few more lines for context.
Link