Somehow during the original run of Enterprise I missed "The Catwalk." Now that the episodes are showing on the Sci-Fi Channel I finally was able to see it. I'm pretty sure it's the only episode that I have never seen before, so on one level I just enjoyed getting to see a new episode of Enterprise for the first time in a long time.
There's also the novelty of the idea of living in a nacelle in the first place. (I had seen this trick re-used later in "The Crossing," but had always wanted to see the original.) And I have to give the episode some credit too for being one of the few times it is actually acknowledged that even Starfleet personel have to use the bathroom now and then. (Although Trip didn't think of it until Travis brought it up. Having a "boomer" along who knows how you really survive in space certainly has its advantages.)
There's also a great gag when we almost get to see Chef . . . but not quite.
I've read some mild criticism of the tech aspects of the episode. I can forgive many of these errors for the sake of enjoying the story, but there are a couple logical gaffes that stand out to me.
First we have the recurring problem of a starship that can't get around an essentially two-dimensional phenomena (along the lines of what happens to Voyager in "Twisted"). The storm is described as eight light years across, but appears to be much shallower. Why couldn't the ship simply go above or below the storm? Sure Kahn couldn't think in three dimensions, but what about Archer or Travis?
The storm is supposed to be traveling at warp, Enterprise has disabled its warp drive so as not to cook the crew as they prepare the catwalk, so why does the storm appear to drop well below impulse as it makes its final approach?
Perhaps both of these flaws can be explained as limitations of the visual effects, but there's also at least one internal inconsistency in the story.
Phlox originally proposes that some portion of the crew could take refuge in sickbay, that it has enough shielding to withstand the storm. Later he pleads with T'Pol for more space on the catwalk so he doesn't have to leave behind any of his animals. When I first watched the episode I thought it was a touching character moment, but when I re-watched the episode it occurred to me his animals were already in a safe spot. They were in the safest spot on the ship other than the catwalk.
I suppose he could have been concerned that they would need someone to feed them over the week or so they were all up in the catwalk, but it seems hard to imagine some arrangements couldn't have been made for at least some of the animals - perhaps ones that don't need to eat very often, or ones that could be left a weeks supply of food without getting sick on it, or some kind of automated food dispenser (which it seems likely he has anyways to care for his menagerie).
When I realized his animals weren't in any real danger it deflated the whole 'emotional plea.' Well, maybe Phlox was exaggerating the amount of shielding in sickbay and it wasn't really that safe of a place to be.
As I said, I found it to be an entertaining episode overall. And while the idea of alien visitors who are hiding what they really are certainly isn't new, I did like that this time what they were hiding wasn't in and of itself any direct threat to the ship. In fact, while Archer struggles with whether or not to trust them, and calls them "deserters" with just a touch of disdain, they are ultimately reasonable and diplomatic, which helps make them sympathetic characters.