The second pilot and the one that sold the show is noticeably different than the other episodes of Star Trek, seeming more like a standalone film than just another weekly installment of the series. Apart from being visually different (with Spock wearing yellow) and lacking some familiar faces (such as McCoy, Uhura, and Rand), it's much more ambitious and exciting than the other early episodes, moving along at a fast clip and featuring lots of action with two superb guest stars driving the story. Unfortunately, these differences spooked NBC, which felt that "The Man Trap" more accurately represents the characters and look of a regular episode (both true) and tried to hide "Where No Man Has Gone Before" by sticking it after a couple "normal" episodes. This, however, put "No Man" after "Charlie X", which is essentially the same story with an adolescent in place of Kirk's friend. (Truth be told, "No Man" probably wouldn't have aired at all had it not been for the simple truth that Star Trek was an expensive show for its time and couldn't afford to bury an episode).
Regardless of all the drama surrounding the making and airing, the drama within "No Man" still holds up today as a fine piece of entertainment. It starts with Captain Kirk, with William Shatner stepping into the character's space shoes for the first time as if it's the fiftieth time. He's comfortable with Kirk from the beginning and gives him a tough interior beneath an easy going smile. Spock, on the other hand, is still a work in progress, with Nimoy experimenting and discovering quite a few things that don't work that he never does again. As for Kirk and Spock, they don't seem to be friends yet, instead sharing a professional relationship that lacks the chemistry Shatner and Nimoy would develop together in future episodes.
Meanwhile, we get a glimpse of Sulu and Scotty, but the emphasis is on the other crewmembers making their onetime appearances. What's wonderful about these characters is that the actors are able to develop them in such a way that they don't feel like guest stars but seem like regulars who just don't make it to the next episode. No doubt these actors have an advantage over future guest stars, since they're able to develop their parts and their camaraderie along with Shatner, Nimoy, and the rest, as opposed to stepping into a cast that already has a bonded nucleus. Nonetheless, Gary Lockwood and Sally Kellerman are two of the best guest stars of the original series, and the show is wise to use them to set Star Trek in motion.
On the other hand, developing the plot around extra sensory perception is a questionable decision. In the 60s, ESP was considered more science (or at least science fiction) than fantasy, and the episode is built upon the premise that ESP is much more understood in the future, giving the writers a launching point to take it even further with "super ESP" Today, however, ESP seems more alien than human to us, and future Trek incarnations would save it for characters like Counselor Troi, making the "human ESP" plot of "Where No Man Has Gone Before" stand out as an enigma.
When it gets down to it, however, the pilot's uniqueness is part of its charm. Even its score is special, though the episode doesn't use the theme song composed to go along with it, using the theme from the first pilot instead (as do all the other Star Trek TOS episodes). And then there's the episode's title, which lives on as a Star Trek catch-phrase, though curiously no one in the episode actually goes where no man has gone before, with the episode going out of its way to mention that the Enterprise is the second ship to leave the galaxy and go through all this. The iconic words, however, capture the spirit of the show, which is probably why they're mentioned (with the addition of a split infinitive) in the opening of every episode.
Is the pilot the kind of Star Trek the public would get to know and love? Not really. But, like a feature film derivative, it's a fun standalone installment.
Remastered: "No Man" gets the royal treatment with feature film quality shots of the Enterprise amidst beautiful backdrops inspired by images from the Hubble Space Telescope. The famous and beautiful matte painting of Delta Vega (used several times throughout the series) is kept relatively intact, though it's given an upgrade with more realistic lighting and texture. (Also, the redone version, unlike the original, reflects the time of day with subtle variations in the Meanwhile, Captain Kirk's grave remains "James R. Kirk", with the CGI wizards admitting that it would simply be too much work to correct it to "James T. Kirk" because of the number of shots it appears in.