I love early Star Trek. I don't mean simply the original series as a whole, but those early episodes of the first season where they made such a concerted effort to establish the setting of the Enterprise and its crew. I really like the interaction amongst the secondary characters as well as the wonderful character moments and exchanges. There's also the effort to create the sense of being far from familiar territory. This attention to detail doesn't really go away throughout the series, but it's not as prominant as it is in these first season episodes.
In this episode Uhura is now in her familiar red uniform. And one little oddity--in the opening bridge shot we her at Navigation. Then later she's back at her regular station. Later still, when they're conducting their "intruder alert" search we see Uhura at the Science console and Sulu at Communications. It's a good scene and a sample of Nichelle Nichols having a lot more than usual to do in this episode. Wish we could have seen more like this later in the series.