Any time you can take an undrafted kid and skate him in 323 regular season games and 46 playoff games, that's a win. Much harder to achieve that with a defenseman than a forward too.
Forgive me for sounding like a sanctimonious jagoff but those 300 games are easy to achieve when it takes your coaching staff 3 1/2 years to pick up on the fact that you're not progressing.
I hold to the notion that it doesn't matter how old a player is provided his physical stature. Once you're at 100 or so games and you are showing almost no progress there is a very serious problem. If the player is really inconsistent but the light comes on sometimes then call it a process. Get him to the AHL let him get his confidence up and keep at it. You just need palpable progress by then. It's one thing to be small rookie Brett Connolly and you're on your back 75% of the time and another to be Jesse Puljujarvi, this Lindros sized manchild that doesn't do anything. Sustr was the latter and did not progress from beyond game 50.
You're not gonna understand the game because you're older, you're gonna understand it because you've been playing and for 300 games our coaching staff couldn't see that Sustr wasn't getting it. Whether it was from stupidity by the coaches or not having a better option within the organization, the Sustr fiasco was exactly that. The guy couldn't even handle bottom pairing minutes.
He was a member of a long list of players who didn't have talent to be placed in the roles they were in over the years i.e Killer, Fillpula, Callahan, Namestnikov in the top 6 and all the problems that came with it and it was the entire reason I defended Cooper during the days we wanted him fired.
But lucky for us we found Jesus AND better hockey players when they mercifully started benching him. How someone can go -2 in less than 5 minutes TOI in a game where you score 5 times is a heck of an accomplishment