No spoilers fromt he first book in the review. :) My review from the first book is here.
Glass was pretty similar in tone and style to its predecessor. It picks up a short time after the events of Crank. This book is also written in verse (I believe all of Hopkins' books are, though I could be wrong), which made for a relatively quick read, if not necessarily easy, due to the subject matter.
In terms of format and layout, Glass was easier to read than the first book. I guess the poem layout was maybe a little less creative, but it definitely helped me understand the flow of the words better, and I didn't need to do nearly as much rereading as I did during the first book. There were a few things that I wasn't sure were intentional - italics generally seemed to be used for dialog, but sometimes, in the middle of what appeared to be someone's sentence, they would be dropped, and then come back again. Not sure if that's a mistake or not. So in a lot of ways, the paperback would probably still be easier to read than the eBook, but there were improvements made in that department. I ended up reading the book with my Kindle on its side with the font at the smallest size, and that seemed to preserve 90% of the originally intended layout.
Kristina's choices over the course of the book are predictable, but frustrating. As with the first book, knowing it is based on a true story is difficult and sad. My only real issue with the book itself was that the dialog didn't seem realistic to me a lot of the time - sometimes, it was great, and other times, I felt like it was a major miss and Kristina didn't feel like an authentic teenager.Crank had some of the same issues, though, and I guess it would have been even more jarring to change some of that in the second book.
I am interested in continuing the series and seeing where it goes from here.