The Equinox Road is a supplement that revolves around ending a Changeling: the Lost chronicle. It offers a lot of specific, actionable advice on subjects like staging a memorable campaign climax or running an adventure where the PCs return to Arcadia. It also offers a bit of woefully inadequate advice for running crossover games. It's not anything an experienced GM would wind up needing, but nobody starts experienced, and so for what it is, it's very useful.
Where the book gets more interesting is when it talks about the landscape of Arcadia and the psychology of the True Fae. They get very abstract and metaphysical. The Fae are Realms within Arcadia, but they are also Actors within those Realms and the Props those Actors wield. It does an amazing job of conveying a sense of the divine, and would serve as an apt backdrop for campaigns where the PCs are themselves peers of the gods . . . were it not quite so wedded to the game's most pessimistic assumptions.
By their very nature, True Fae are total dicks, because though they are complete and omnipotent within themselves, if they retreat into solipsism, they wind up amplifying and echoing their own chaotic internal impulses and losing the signal in the noise. It is only through opposition to other sovereign minds that they are forced to maintain coherence. Meaning comes from confronting a reality outside themselves, and pushing up against the limits of their power. They are an enemy to all other intelligences because only enemies push back.
Philosophically, it's all very thought-provoking, but I think it undermines the endgame by making Faerie a place of pure pandemonium. It is a war of all against all, and to the extent that faerie things interact with the mortal world at all, it is as exploiters and abusers. So when you say that high-level Changelings have the potential to become Fae themselves, it is only ever a temptation to corruption (and thus no temptation at all to a player, except as a tragic coda to their character's story).
I can't say with certainty that the possibility of "good" Fae would have enhanced the game, but I do have to look in askance at the final chapter's advice that "the phrase 'adventure' [...] should serve as a warning. Care should be taken to make sure that the quest aligns not only with the themes of Changeling, but the World of Darkness as a whole. Even a glorious knightly sally into the Hedge should be grim and dark, more Band of Brothers than King Arthur."
First of all, King Arthur? Context implies that they're talking about the 2004 movie, and that's just embarrassing. I remember that movie, and it is baffling that anyone would think it a useful cultural touchstone, even as early as 2008.
But that's just me being petty. The real issue here is Changeling: the Lost's relationship with horror. Horror is an essential ingredient to Changeling: the Lost's formula. I often find that when text is most in danger of getting just a little bit too twee, there's a bit of something awful or grotesque just around the corner to ruin the mood. However, horror is just part of the recipe. Wonder, intrigue, romance, and whimsy are all just as important, if not moreso.
And that's something C:tL 1st edition didn't quite get, at least not in its first batch of supplements. It's a good horror game, but it has the potential to be a legendary urban fantasy game. And I'm not sure that idea was even on White Wolf's radar when The Equinox Road was being written. That's perfectly understandable, of course. These things often only become apparent with historical distance. But I can't deny that it was pretty disappointing to see GMing advice that was pretty much, "stop having fun, your game needs to be grim enough for the World of Darkness."
So once more, we have an example of a perfectly good independent game being held back because of its connection to a setting that really only exists in potentia. The "World of Darkness" is what you get when you strip away those elements the various White Wolf games don't have in common. That's probably why the crossover advise is so uniformly disappointing. By their very nature, crossover games move their characters at least a little bit into the poorly-thought-out meta world.
Ultimately, I'd say that The Equinox Road is about 75% of what I want from a Changeling: the Lost endgame book. I'd love it if high-Wyrd PCs could have truly world-shaking powers, if Arcadia were a place with more ethical nuance, that could hold promise as well as peril, and if the optional free-form narrative rules that governed the Fae could dovetail just a bit more elegantly with the PC scale. However there are a lot of good starts here, and even if the book doesn't give me everything I want, it provides a solid foundation if I were to decide to build an endgame of my own.
UKSS Contribution: Once again, the specific setting examples are the best part of a Changeling supplement. This book is a little trickier, because the Arcadia locations are also all faeries, and thus the best are hard to adapt and the worst are too vague to serve as inspiration. However, there was one magical location that hit the sweet spot: The Twilight Wood.
It's a forested swampland where the trees are so thick that hardly any sunlight penetrates to the surface. It is home to fireflies in a rainbow of colors and haunted by will-o-wisps. Some of the trees are haunted by the souls of the unhallowed dead and move when they are unobserved and bleed blood-red sap when cut. I figure it will be a pretty good home for the Frog Nation.