I'd give "Fight or Flight" 3 stars out of 4. It was an episode that did a lot of little things whether demonstrating how making excursions to unknown alien ships is as simple as a jaunt down to the transporter room or the prolonged periods of boredom crews might experience before encountering something interesting or the fact that the NX isn't the baddest ship out there.
Once again B&B get the atmosphere and attitude right by making this experience new and fresh. The episode oozed with tension and had a spooky vibe to it. I always liked this type of episode on TNG where the crew came upon some mystery to be solved. Unfortunately, unlike TNG episodes like "Night Terrors", "Clues", "Schisms", "Remember Me" the revelation about the aliens wasn't that interesting.
Again B&B did some good work with the characters and unlike the early episodes of DS9 or VOY, this crew's interactions were more interesting to watch.