I think it is fairest to compare this to One Ring Strider Mode or Ironsworn/Starforged. In this company I think it falls a little short, but perhaps it is just different.
There is no character progression. You can shift your stats a bit but you do not grow from Zero to Hero in this one. If that's important to you this might not be for you.
About 2/3 of the book is just nicely organized Star Trek lore. If you are a Trek fan it is worth buying just for this.
There are some great random tables/oracles that are very Trek specific. Again this is one of its strengths.
Character creation is a drawn out process. If you enjoy making detailed characters you will like this. If you rather have simple characters, then you may struggle with this. The problem is no one really acts alone in the star trek universe. You are part of a crew. Captain's Log does not deal well with this and the complex character creation is not helpful when you really need a crew of several people. Pre-gen crew members would be a welcome addition to this as would pre-gen spacecraft. Getting ready to play is a multi hour process to generate ships and crew. Captain's Log also doesn't address companions or allies in its play through, a major oversight in a Star Trek game. I would love to have a catalog of 40-50 crewmembers already generated that I could assemble into my bridge crew or take on away missions.
The weak point is the 2d20 system. But honestly you don't get to the rules of the game until chapter 5, 179 pages in. Then all the rules are laid out in a fairly brief 45 pages. This is not a "fiction first" system. In examples of play the book repeatedly has you roll then afterward narrate the details. Combat is always a minor part of Star Trek but it is important. It feels very squishy and abstract, but then everything feels a bit squishy and abstract in this system. First one to land 3 hits wins. After playing for a couple hours to where I felt comfortable with the system I converted my characters over to Savage Worlds and had much more fun and didn't look back. Still using the oracles and a lot of the background info (I already know most things Trek but it is a nice reference.)
The overall structure of the game focuses on what feels more like a writing exercise for an episode script. Each mission has 15 scenes divided into three acts and many of the things that will happen in these acts are known before you begin. You fill in some blanks along the way but it very much feels like the episode outline is developed before play begins. I tried this before ultimately rejecting it. I don't need my RPG to have an episodic story arc that is quite so neat. I like multiple overlapping dangers and surprise twists at any point, and this playstyle didn't seem to lend well to that.
As to exploring, something that One Ring and Starforged does very well, this doesn't seem to capture it at all. I would have appreciated something of a hex map crawl like Starforged, One Ring or even Forbidden Lands.
A bestiary of villains, both individuals and ships, would have also been nice but is completely missing, though combat is so lacking in detail that I don't know what stats would actually differentiate a rabid tribble from a gorn.
Bottom line, The oracles are nice and it is a serviceable compendium of Star Trek lore, but I would recommend hacking in an entirely different system to play, one that excels at sandbox exploration and has more meaningful use of companions and character development. I would also recommend a more fiction first approach.