The Noble (a 5E Warlord, basically) is by far the best thing here. If a smallish writeup that basically takes that idea and does it reasonably well is worth the price to you, buy it. Otherwise, don't, because the rest ranges from nothing to write home about to actively bad.
It's dubious whether some of these concepts - particularly the Feywalker and the (somewhat misleadingly named) Occultist - are interesting and archetypal enough to support their own classes. Several of them could be done more satisfyingly as archetypes for classes that already exist.
But even the good ideas are not, in general, executed well, especially from a balance standpoint. The Alchemist - the one I was most looking forward to conceptually - can get Cure Wounds as a ritual starting at second level (and eventually, at 20th level, as a cantrip), which dramatically alters the game's balance, basically flipping a huge middle finger at several of the game's underlying assumptions, not least the entire concept of hit dice. A party with a competently built alchemist is almost not playing the same game anyone else is. On the other end of the scale, the Occultist appears laughably weak, so obviously inferior to all the other melee classes that, even if a player really liked the concept, the only thing I could do in good conscience is steer him or her toward reskinning a fighter or barbarian to incorporate that concept, rather than using this class as written. With these two examples in mind, I don't know why I'd trust anything else in the book enough to let it into a game.
The formatting is also kind of dodgy. The back cover promises that the classes have been revised and expanded, and this was also strongly implied in the Kickstarter campaign that resulted in this book. That's kind of hard to credit. I haven't got the relevant EN5ider issues that would let me say for sure, but it sure looks like they've just directly copy-pasted a bunch of magazine articles (what these classes started as) together into a book, with at most superficial changes to use a unified trade dress. The Alchemist, for example, is still broken into three separate articles. Even dirt-simple things that would have taken literally seconds to fix (the Noble's chapter using a completely different naming convention from the others, for instance) haven't been changed. There are feats (some of them of potential interest to more than just characters of these new classes) scattered all over the book instead of sensibly compiled together into their own appendix. (Also, one of the feat names hits a pet peeve of mine - while I'm reliably told both forms are correct, I will never not wince when people say "Cardshark" instead of "Cardsharp".) All of this could probably have been fixed in an afternoon of InDesign work by a minimally competent layout person, preferably one who was also (or was working closely with) a good editor. Overall this aspect of the book feels very lazy.
One other thing that makes this project feel a bit of a Frankenstein's monster is the art style - or rather, the many art styles. Many different artists have been used, as well as what look like a few public-domain historical pieces, and the overall result feels every inch the stitched-together mishmash it is. If there's a unifying thread to the art here, it's that most (not all) of the art styles used are a bit too cartoony for my tastes, though even that manifests in varying ways. But that bit is admittedly very subjective.
Don't let this review turn you off EN Publishing altogether - many of their adventures are just excellent. But this particular product was very disappointing to me.
[2 of 5 Stars!]