Trouba is definitely more comfortable this season. Last year with Ruff leading the defense and being partnered with Skjei, he was definitely exposed. Smith was not the ideal partner either once Skjei was moved.
Now, with an actual defensive coach and some structure, he looks a lot better, all while being partnered with someone that we almost all expected would not be NHL ready in Miller. Missed time with a fractured finger, came back early from it, likely when it wasn't 100%, but he could go.
On top of that, he's definitely grown into a leadership role. Quinn's comments about how he led the room during intermissions last game was important. Quinn can't be the only one relaying the message (in spite of people complaining he wasn't in the room or saying Quinn is so useless that he didn't need to be there). Eventually as a team grows, the players have to run themselves to some degree. Trouba doing that is important for overall team growth. The younger guys see this and can draw from it in the future, when they will be in that kind of role.
Last season there was plenty to complain about. This season though, he's been as advertised and becoming part of the leadership group of the team.