The past few seasons of "Stargate: Atlantis" have fallen into a despairing pattern. The first half of each season is packed with solid plot and character development; the second half is far more episodic and tends to concentrate the least successful episodes together in one lackluster run. "SGA" is hardly the only such victim of the Sci-Fi Channel scheduling curse: "SG-1" and "Battlestar: Galactica" have both experienced the same inexplicable pattern.
As diverting as this episode was, it was also relatively self-contained and had very little to do with the rest of the season. There's some hint that it connects to McKay's character arc, particularly his recent problems with Dr. Brown, but such moments are fleeting. Most of the episode is a matter of waiting for the inevitable escape, which proceeds at a surprisingly slow and plodding pace.
Carter, Keller, and McKay all get their chance to offer a clever solution to the problem, avoiding the possibility that Carter would show up McKay in a crisis situation. It's just as surprising that Keller managed to hold her own; with a little more luck, her solution might have been effective. In the end, however, none of those solutions resolve the problem; instead, at the last possible moment, a solution presents itself.
I'm of two minds regarding that resolution to the crisis. On the one hand, it keeps all three characters on a level playing field, because none of them succeeded. Unfortunately, that means that the writers had to resort to a massive plot convenience to ensure that the characters would survive. And since there was absolutely no chance that any of the characters would die, there was little or no tension.
In the end, this was an example of a failed "bottle show". While the characters were in crisis, none of the character exploration that usually comes with a good "bottle show" was present. Carter was just as bland as she's been since taking command of Team Atlantis, and McKay was slightly less panicked than usual (perhaps a minor step up from "Quarantine"). Keller got some much-needed screen time, but other than possible interest in McKay, the long-term gains were minimal. The result is an episode that feels unnecessary.