nicely done. I particularly like the first two because they appear more "situational" in the sense that they don't seem posed at all.
Also, people with a few years behind them tend to display a lot of character and personality in their faces and that is certainly the case here.
You haven't forced a "dramatic lighting" on them and it doesn't appear "arranged". This is how you'd see them with your naked eye in that setting and they come across natural.
The gentleman in the second picture is oozing character and is an excellent model.
The lady in the first appear not even to know that a picture is taken, which is a great quality to have.
The young man in the third conveys warmth and mischief all at once.
For your studio set-up I'd suggest that you experiment with moving the model a little further away from the background and maybe change your depth of field to blur it a little. The texture in the background is - to me - a little bit distracting.