There's only one thing that makes this episode worth watching…
That is Sheppard climbing the outside of one of the towers. It's a great visual.
The rest of the story is boring. The city goes into (a false) lockdown mode. This strands several characters allowing them to have "character moments." Carter is stranded with Zelenka. Sheppard with Teyla. McKay with Katy Brown. We get the expected character interaction. Teyla may or may not go into labor. McKay may or may not propose to Brown. We really don't learn that much more about them.
Cut the episode from the series and you're no worse off. It really adds nothing.