I used this textbook in college after finishing the Genki series and studying for a year in Japan. It's not Genki, but it comes really damn close compared to all the other textbooks on the market.
By far this book's best point is that it covers a HUGE amount of useful grammar, most of which it gives pretty good explanations for, and all of the grammar points appear in the dialogues and readings. Occasionally I would go to my professor or whip out my grammar dictionaries for further clarification, but the book covers at least the very basics on them all quite well.
We only covered chapter one through eight before I graduated, so I studied the remaining chapters on my own over the past few weeks. Most of it is clear enough to learn with out any additional assistance. (Though it's definitely meant for the classroom.)
The vocabulary it covers are pretty good, though you might want to supplement it. They list all words in the readings and dialogs that you may not have seen before and that have not previously been covered in earlier chapters. If you feel like you need more vocab, there are lots of good lists available online.
Similarly, a lot of useful kanji are brought up, but the book doesn't focus on them. As the authors say in the introduction, they didn't set out to make a kanji textbook. So if you're looking to study kanji more intensely, I personally recommend investing in a solid dictionary and just go at it. :)
There aren't a ton of exercises in the book itself, mostly just discussion topics and things. If you want exercises to practice the grammar, invest in the workbook. You will get about 3-8 chances to test your understanding. Sometimes they do seem to be lacking on chances to use the difficult ones, while having too many of the simple ones. So that can be a little frustrating.
The listenings for the text aren't amazing, but I don't think listenings ever are. They're REALLY slow in a lot of the dialog, but that's probably good if you just came from Genki. The listenings for the reading sections are a little more challenging.
One bad point is the level of politeness a lot of the "American" characters have. Susan even uses keigo on her host mother sometimes, but when I lived with a host family they kept begging me to talk more informally. They also seem a little too polite in almost all situations. From what I've observed in Japan, it seems kind of unnatural. Further discussion on WHEN to use keigo would really improve the book, along with more practice using both polite and informal language in the proper situations.
After completing everything, I feel very confident for N3 this year. If all of it were covered in a classroom setting and studied hard (I know I suck at remembering vocab and kanji long-term) I think most students could handle N2.
It's got it's downsides, all textbooks do. But I've looked through a lot of texts at this level and feel it's the highest quality, most comprehensive of them all. And a lot of it's negatives are easily remedied with grammar and kanji dictionaries (which you probably have at this point) and possibly the help of your favorite Japanese professor. :)