This episode shows what the Federation is all about. Sharing with various species and cultures in peaceful cooperation. It shows how diverse these cultures can be, in not only looks but in idiosyncrasies.
I think some of the ideas offered in this episode are intriguing and brilliant! The void is a nasty trap and the thought of it exsisting is creepy. Imagine getting caught in one and then before you can figure out what went wrong, you are raided by passing ships also caught in the void!
I also find the character, "Phantome" and how he begins to use musical tones for a language is inspired!
I love how all this wonder is wrapped up in a nice warm "Federation" blanket.
Gene Roddenberry would be proud of this episode!