I got this as part of a charity bundle, but I"d say that it's worth paying cover price for anyway if you're a heavy Mutants & Masterminds player.
I'm unfamiliar with the Hope Prep series; this is my first exposure to it, so I'm not sure how it integrates with the other available Hope Prep titles.
The text is a little dry in places -- it IS a high school handbook, written completely "in character" after all, but there's color commentary added by three students, who help to keep it interesting and put a human face on the document.
While, I thought the comments written in the margins are a great idea, the execution suffers. The fonts aren't the easiest to read and this isn't helped by the color selection and placement. Frequently the notes ran vertically (90 degrees from usual), which is a minor annoyance on the printed page but a major drawback when trying to read on-screen. Still, they had the forethought to place them on a different layer so you can print "unmarked" copies for your players. I think the overall presentation could be improved with wider page margins (in which to write notes) would have helped considerably, as well as different fonts. Even scanning in handwritten text would have been a better choice.
In the "Notes" section (and in the small rules section), the three students talk extensively about the cliques, and established social classes of the school, which was particularly well done. It gave me flashbacks to my own high school experience, which, while unpleasant for me, is a testament to this piece's authenticity. When I'm done writing this review I'm going to pine for hot girls that'll never give me the time of day.
As a GM, I'd've liked to have seen stat blocks for a typical (or archtypical) representative of each clique,-- but maybe those are included in some other product. They do have stats on the faculty, which is pretty nice.
As a player, I can't think of anything that's missing. It's a good world-building document.
If I could get my gaming group to be the least bit interested in Mutants & Masterminds, I would definitely investigate the other Hope Prep books.