Having heard back from all critiquers of my YA novel, I have gone ahead and cut the journal format from the book. To those who haven't read it, this means little to you, but I'll speak in generalities the rest of the way to make this more accessible.
The reason I made the change is twofold. First, and most importantly, I always had issues with it, and if there's anything I've learned it's that when I've got reservations about something in my story I'm usually right. A lot of times I refuse to listen to my gut for all sorts of bad reasons, (my ego being one) and stuff I know doesn't work stays in the story for far too long.
Which brings me to reason number two. A number of those who read the novel shared their concerns over the format. When I put this together with reason number one, it becomes pretty evident that there's a problem. My experience with critiques is that, with very few exceptions, the concerns readers have are the same ones I have but have been too stubborn (or scared or self-delusional or all sorts of other stupid emotions that get in the way) to remedy. I'd say 90 percent of the time a reader's concern affirms what I already deep down knew to be true.
So the journal format goes, and getting rid of it was much easier than I expected, both emotionally and physically (I probably deleted a total of a thousand words is all). And even though I had to take out a couple of pretty sweet lines, the book is stronger for it.
Now I've just gotta figure out a plot.