Well its about time I got back to this; just finished reading it on Wednesday.
The TL;DR version:
I would agree with Borommakot's assessments. It is definitely an easy read, but I don't mean that in a negative way at all. I found myself so engrossed at times 100 pages would fly by without me even realizing.
If you are a fan of Ahsoka as a character then this is a must read. If you aren't, its still a fun story with insights to the thoughts and emotions of those living in (and fighting against) the newly formed Empire, and should be on your list of books to read. Though if you really dislike her (and there are apparently many who do), you don't care about the story, and are reading it purely for lore additions, then there might not be enough here for you.
Now for some more specific likes and dislikes (major plot points will be in spoiler tags, but if you want to go in completely blind, stop reading here).
The way it handled exposition was well done; instead of dumping everything that happened between the Siege of Mandalore and the beginning of the book, short flashback chapters (signified by grey pages and italicized text) every now and again gave you just enough to satiate your curiosity without bogging down the action.
Going in I thought the book would solely follow Ahoska and her thoughts (or at the most a few characters directly involved with Ahsoka's arc), but was pleasantly surprised at the time dedicated to Bail Organa (and even the short sections on Obi-Wan and Anakin). On top of great emotional moments from him (his fears that Leia will inherit Anakin's Force sensitivity, and his reoccurring nightmares about Order 66) and details on the way he went about trying to build the rebellion, we also get confirmation on why Bail didn't tell Obi-Wan about Ahsoka after finding out she was alive (which was somewhat of a plot hole after her inclusion as part of the rebellion in Rebels). His thoughts on R2 were great as well, and also show him as one of the few people keyed into how special of an astromech he is.
The basis for the main Imperial conflict of the book (using up Raada's resources for food) I thought was well chosen. It was able to show, even so early in Palpatine's reign, how ruthless the Empire's methods are in getting what they want, as well as a real issue they would have faced in maintaining their vast forces.
Now I'll admit I'm not very well read when it comes to printed SW media (canon or otherwise), so i can't say the book is unique in this, but I enjoyed seeing the SW world from a non-human; the part when Ahsoka notices Vartan's male pattern baldness and realizing she doesn't understand how hair works was amusing. Other world building bits (such as movies in the SW universe being called "Holonovels") were nice additions.
I did have a few sticking points however, one story related and having to do more with an overall canon change:
Story Related:
With Ahsoka being shown as being a great mechanic, her not realizing the scrap she was collecting could be used for a lightsaber until after her vision seemed a bit off to me. I get that she probably never planed to build a lightsaber again, so she wouldn't be thinking about it. And sure, the important bits were harvested from the Inquisitor's lightsaber, but one would think after building 2 already, the thought of "hey these could be used for lightsaber innards" would have have at least crossed her mind.
Overall Canon:
Getting rid of synthetic lightsaber crystals in favor of Kyber across the board was one thing, but this whole "the crystals turn red because its bleeding since the Dark side is bending it to the user's will" seems a bit too much. We get it; the Sith are evil. No need to be so on the nose about it. I would have been fine with the crystals just turning red based on the nature of the person attuning them (which is the new explanation for different lightsaber colors), but making the crystals so anti-Dark side seems too far.