This episode feels like it needs two--maybe even three--separate reviews: one for the background, one for the actual story, and one for being an Arrow episode (in theory).
The background of this episode made little to no sense and brought up a lot of questions and then instead of providing answers, for the most part it brought up more questions. (Why does everyone keep saying there is NO crime?) This is to an extent understandable as it is directly following Crisis, which changed who knows how much of the universe. But I really wish they had taken the time to explain things a little more, instead of bringing up random facts that made long-term Arrow fans go "wait, what?" and then immediately dropping them and moving on to something else like a hyperactive child on a sugar rush. I found the changes intriguing, and look forward to how the spin-off resolves and explains things, but I found the whole world-building, background info thing rushed and overwhelming in this episode.
The story itself (barring anything to do with the setting in an alternate 2040) was good, but not great. There was a nice tension, throughout the entire episode, immediate stakes and the beginnings of a story arc with Laurel's future info, which worked well. The pace was decent half the time and a hair rushed the other half. The character interaction was solid, very well-written, but I do worry about it in terms of a pilot for a new show as a lot of it (especially the Dinah/Laurel interactions) depended on a few seasons of Arrow for background knowledge. The characters themselves were as vibrant and real as Arrow has always done. The storyline was not perfect, too much crammed into too little time, but it felt like standing on the verge of something that could be very good, even great; it felt like a pilot--a little taste of all the varied things the show has to offer, a little intrigue to hook you into coming back--and it genuinely got me excited for the show and willing to give it at least a few episodes to see if it finds its feet.
I really do hope the spin-off does well and I have high hopes from this that it could.
Now, as an Arrow episode, I'm not sold at all, especially as an episode from season eight. As I have mentioned several times, this was a very fast-paced, somewhat rushed episode throwing a lot of new information at the audience about every other second, which was something of a hiccup in a season that has otherwise been a farewell tour (except for Crisis), a season that has been steeped in nostalgia and has balanced high stakes and tension and rapid-fire fight scenes with a slow, somewhat melancholy pace that took time to honor the history of the show as often as possible. This didn't feel like much of an Arrow episode at all (not just because of the absence of Stephen Amell, but tonally), much less the penultimate episode of the final season. I would have liked this a lot more if it had not been aired as an Arrow episode.
So, basically, great pilot for a new series, not a good Arrow episode, especially for its place in the Arrow lineup.