The greatest thing about this episode is that it features Leland Orser who is one of Hollywood's most underrated actors; as usual he gives a superb natural performance. We don't see enough of Leland Orser like others of his ilk, because they're too good; they act as though they aren't acting and so most of the audience are so convinced that they don't realise what an incredible job they're doing - especially with the kind of characters that Leland Orser plays. So if you want to see a master at work, then watch this episode.
Apart from that the story works really well and is shot in a grittier hand-held style that suits the dark atmosphere and it's a big departure from the tight gloss of the usual Enterprise episodes - it's all about the characters; no CGI or tech-speak. Perhaps you could compare it to an episode of the X Files; it looks kind of similar and the plot would work in that series.
In total it's very enjoyable from the first scene to the last; it keeps moving, every sequence adds to the storyline and it keeps you glued to the screen right the way through. Over all it's a triumph and an episode you could watch as a stand-alone and get what's going on in this series. It was also good to see Archer and T'Pol out of their normal context; though I'm glad it doesn't happen too often - this episode goes along with the long tradition of Trek crews finding themselves on Earth in the past, or in pseudo Earth societies on other worlds.