The primary thing that strikes me, 49 years after the pilot episode of Star Trek, is the galaxy Roddenberry was trying to create. The colonist illusions and the Rigel 7 mindscape paint an Enterprise whose primary duties include going from Slowship colony to Slowship colony, bringing humanity back into a unified whole. After five decades of Star Trek delving into the Federations political and military interactions with other cultures, I’d forgotten how much of the original Star Trek focused on painting this picture.
With what we know from future canon about the Eugenics Wars, Zefram Cochraine’s flight, and the immediate species-wide apprenticeship under the Vulcans, Humanity must have been sending relativity ships to the distant stars for years prior to the final devastation of humanity. The frustration of Archer and the heads of the NX project must have been immense, thinking of all of those colonists stranded out there among the stars, refugees from a dying earth that was saved by First Contact. Ex Astris Scientia, indeed.
Finally, we see right from the start in “The Cage” that Star Trek is going to use the future setting to do varying levels of social commentary. The Talosians present a science fiction take on Television culture. Joyriding in alien experiences, it’s easy to look back and see the foreshadowing of ‘reality’ programming as a dark and terrible thing.