This episode boils down to a simple premise, isolating Sheppard from the rest of Team Atlantis for a rousing adventure with a new group of disaffected humanoids. In this case, the episode has less to do with psychological exploration of Sheppard's character and more to do with a stripped-down action-driven tale.
As always, such an episode finds success or failure based on the strength or weakness of the opponents. That puts a lot of pressure on the Travelers, and particularly Larrin, to prove themselves interesting. For the most part, that goal is achieved. The concept behind the Travelers is consistent with the state of play in the Pegasus Galaxy, and opens up interesting new possibilities.
The Travelers have abandoned worlds completely on the theory that living in ships will lessen the chance of culling by the Wraith. If nothing else, they can see the Wraith coming, avoid them if possible, and defend themselves more readily. They've heard about Team Atlantis, and they know that certain members have the Ancient gene. The Travelers have taken possession of an Ancient battleship, and they plan to use Sheppard to create an interface.
The Travelers are very much like a space-borne Genii; they have strong resources, a relatively clear agenda, and little desire to forge an alliance with a group that has created problems since their arrival. At this point, at least, the Travelers are far less complicated than the Genii. Sheppard only deals with a handful, and the only one of importance is Larrin.
Larrin is, of course, an attractive woman with a bit of edge to her personality, and that seems to serve a dual purpose. The fact that she's eye candy was no doubt considered useful to the producers and the network as fan service, and it plays into Sheppard's reputation as the "Captain Kirk" of Team Atlantis. On the other hand, she represents the kind of female personality that has been lacking on the series.
The premise, as I mentioned, is simple; Sheppard and Larrin battle each other for control of the Lantean battleship until Sheppard's bid for escape brings the attention of the Wraith. Then, reluctantly, they must work together to survive. Sheppard's friends arrive just in time to save him. Without the interaction between Sheppard and Larrin, there wouldn't be much distinguish it from several dozen such episodes on several other shows over the past several years.
In the end, it's a competent enough episode, if overly familiar at the core. I liked Larrin as a potential ally for the future (or even as a potential enemy), and the concept behind the Travelers has potential. This wasn't one of the best episodes of the series, but it certainly wasn't among the worst. Let's just say this season's new recurring guest character is a lot less toxic than Lucius.