There was a recent Skype interview of him posted here by the Amerks in house reporter. Skype isn't flattering to anybody but he still looks so pudgy and soft. Some of that is genetics but I think it has more to do with his commitment to physical conditioning/strengthening and diet. Sam Reinhart came back after his rookie season looking noticeably different, his neck was much thicker, shoulders bigger, less baby fat.
I think Mittelstadt has just had it too easy. That decision to stay in high school because he wanted to win a championship with his buddies really wasn't a good sign. Whenever he's interviewed about his struggles he always answers 'i'm not worried, it always has come around for me, i just have to be patient' - I think that is a very honest answer, he believes if he just keeps playing hockey everything will fall in place. NHL players are driven, they get stronger and faster, they hire nutritionists/chefs, hire skills tutors - he doesn't seem to get that part of it yet, it should be obvious to him by now what he has to do to be an NHL player.
He strikes me as a kid who if he doesn't succeed in the NHL it won't bother him, he'll be back in upper middle class Eden Prairie and with his connections and fame he'll get into some business and live a good life.
He's similar to Alex Nylander, just don't think either of them completely gets it.
The difference between Alex Nylander and Mitts is that Mitts was straight up rushed. While he did want to go pro after his first year, the Sabres should have known better to keep him there for another year. Nylander has 84 games in the NHL and Mitts played 114 games and got drafted a year after Nylander. Mitts wasn't rounded enough to play in the NHL, and should have had another year in college and at least a full year in the AHL before being brought up.
I don't think he's taking it as easy as he was, but I think he's happier about his own play and where he is than he was previously. The AHL coach got him to play in all situations, taking PK draws, blocking shots, be much more responsible on both ends of the ice, with and without the puck and also let him make up for his mistakes. That is how you're supposed to coach and kid and the AHL is what he's needed. He didn't need that 77 game season last year in the NHL, as he should of spent that to learn how to be better for the NHL, than to just expect to just be good anyways.
He's still raw, but he seems to be young, motivated and getting the right kind of practice, play and training that he definitely needed. Give it 2 or 3 years. Even if he isn't topping 80 or 90 points a season, he'll be a good 60 to 70 point player that can work both ends of the ice.