O'Connor: Negative. Sam likes having people around to protect him, but O'Connor seems the sort that could kill you for no reason at all. Not reliable.
Clem: Somewhat negative. Sam didn't like being rebuffed so quickly the first morning; he's used to people liking him a bit more than she seemed to. Fears that she's too close to O'Connor.
Sammy: Positive. Friendly, well-connected, and attractive; definitely characteristics Sam looks for in his female companions. If she offered to take him to a quiet back room, he wouldn't say no.
Heron: Neutral. Hasn't seen him do or say much. Seems competent, and Sammy seems to like him.
Icarus: Neutral. Again, Sam hasn't really seen anything positive or negative from him.
Johnny: Positive. His killing the barghest bare-handed made a great impression.
Fionn: Neutral, slipping negative: Sam doesn't get along with tech-heads in general, and the only useful thing he's seen red do so far is find the diner. While he blames any problems that stem from the Ares Mart affair primarily on Clem and O'Connor, he feels that Fionn should have been able to keep them under control.
Of course, what I've seen and what Sam's seen are different, but that's how it is.