I was reading it in the ebook format, and i've got to say that although there are a lot of advantages to ebooks in terms of convenience and stuff, i still prefer the "real" thing. Of particular note is the ability to figure out how far you are in tbe book by tactile means =P
I had gotten absorbed in the book and was cruising along, and got to the end of a pretty innocuous chapter. And then i tried to go to the next page. Nothing happened. Not that that is unusual, there are numerous times where i fail to swipe a page in the exact right manner, and some cases where i'm _not_ trying to flip pages but accidentally do so anyways. So i swiped again, more carefully, and the page slid over a little bit but then bounced back.
Only then did i look down at the bottom of the page to see that i was at page 437 of 437. Without the feel of the book in my hands i'd completely lost track of how far i was through the book, though it certainly didn't help that it ended in a place that didn't really feel like and ending to me. (And when i checked online it seems quite a few other people feel the same way. Supposedly this was just the first half of what was originally intended to be a single book before it got too long, and it definitely feels a bit like that.)
This isn't even a problem i normally have with audiobooks, since i rarely listen to them for much more than 30 minutes at a time (ie, about the length of my commute) and i'll generally glance at the time remaining as i start and stop the book at either end, so i'll generally have at least some idea of when the book is going to end. Not to mention that most of the books are split into two or more pieces, which means you get at least one bit of "you have reached the end of this part of the audiobook" message, letting you know you're 1/2th or 1/3rd or whatever of the way through. Usually when i get towards the end of a book i'll start thinking of the time left as X number of commutes left, though in the case of especially compelling books i'll sometimes break down and start listening to it outside of the car as well.
But anyways, back to "A Rising Thunder." Unlike the last book nothing really surprising happened in this one, at least not if you've been paying attention at all. Everything seemed to kind of be running on rails while dangling issues from the last book got resolved and things get set up for the big action in the next book (at least i sure hope there's some big action in the next book!) It certainly didn't help that there were a couple chapters devoted to going back in time to fill in some not especially exciting backstory on the journey the "secret agents" took from Mesa back home with the news about what's been going on there. Since their actual arrival and the results of that information were kind of they keystone of the previous book those flashback chapters seemed both confusing and unnecessary, unless there's something important i missed in them.
Also, let's see if you can spot the patented "let's jump into the middle a battle simulation without telling the reader it's a battle simulation so maybe they'll think the characters are in an actual fight" maneuver :)
All and all it was reasonably well done filler, and obviously i had no trouble getting absorbed into it enough to lose track of where i was in the book, but it was still just mostly filler.