I'd take him anyday over Roman Polak
As a player? 100000%. Helps explain why McAvoy has much better xGA stats. As a puck mover? Sure maybe. But these are both some of the lower end puck movers in the game.
Miro IS a better skater. And that enables him to be better at carrying out of the zone than McAvoy which the numbers bear out. Although the difference from them using their skating to cut off zone entries is about the same. Heiskanen's skating is special and is VERY obvious for folks that only seem them both play a couple times a year. He also actually played 82 games, which McAvoy has not come close to doing.
Not that McAvoy isn't a very very good puck mover, but Heiskanen is special. And the little injuries that McAvoy keeps getting? I dunno. Sometimes it's just random (Pasta couldn't stay on the ice when he started). Sometimes it's a pattern. Too early to say.
But those are the only things you can say he is clearly better than McAvoy at.
McAvoy was substantially better at preventing scoring chances, shots, and shot attempts.
McAvoy was substantially better at scoring points, xGF, and shots for rates. Heck they had the same amount of even strength points despite McAvoy playing 28 fewer games.
Some of that is OBVIOUSLY from him playing on a better team.
But its also a team that missed the playoffs two years in a row before McAvoy joined the team. And then became a contender. And McAvoy is a BIG part of that.
I can understand people voting for Heiskanen. His skating is wonderful and he did a great job, especially in the playoffs. And if you want to take the injury stuff into account, McAvoy has more risk attached. But the "LOL only Bruins fans should be voting for McAvoy" takes are embarrassing (not that you said that, mostly just the usual blue and white wearing suspects). To me they are in the same tier of "young #1 D with big upside that it will be fun to see progress".