Sounds like you're getting pretty good advice here. It all depends on the combination of the instructors, the students, and the art itself. It varies place to place, art to art. There are boatloads of charlatans in martial arts, so keep your bullsh!t detector on at all times. It's your responsibility as an intelligent consumer to be skeptical. Smart instructors will realize that.
In my opinion, one thing you should look closely at is the social dynamic of the class as a group. Are the instructor-level people friendly and open with everyone else, or are they rigid and closed? And even with that, there is no 'right way', but there is a 'most appropriate way for you'. I strongly prefer a very open, informal communication platform in the dojo. I like seeing smiles.
As for the art itself, my major suggestion is to pay close attention to their use of position and balance, particularly that of the 'opponent'. A smart art will compromise the opponent's position/balance and capitalize on it, and make explicit mention of that fact in class. You should not have to 'fight' to win anything. Science before violence!