I second what sayyadina says. The editing is appalling, and I'd accept a small bet that the editors for the two books were different - there are multiple continuity errors between the two books. Shame, as there are many cool moments that deserve to be in a more carefully polished book. (Book, singular. There's also a lot of waffle that could easily be cut, turning this into a single tight, exciting book).
On the story itself? I'm unimpressed with a lot of the 'development' of various characters. I frankly didn't care whether they won or lost by the end of Battle Ground, I had no attachment to most of the surviving characters.
In the spoiler section I created a thread that explains the continuity errors, I think. I don't believe it's bad editing at all. I think it is (mostly) deliberate decisions made by Jim for a specific purpose. The title of that thread is "Dresden Files Continuity Errors – There aren’t any." Here's link to it.
https://www.paranetonline.com/index.php/topic,53735.0.html For the person who won't get BG until Christmas, don't go there now. That thread is in the spoiler section for a reason, though now that I think about, almost nothing from BG is in it.
My feelings about BG are mixed. My favorite parts of BG aren't the battle scenes. I really enjoyed watching Harry interact with some of the heavy hitters of the supernatural world that mostly happen before the battle. I also liked how future developments were set up in the final chapter. I thought that was a much more interesting chapter than most denouement chapters, of any series.
I'm not saying the battle scenes were bad, far from it. However, if I compare BG to another book with tons of action; Changes, it doesn't come off as well. Changes has far more changes of pace and interesting bits of dialog and character development. In BG, once you get into the battle, or I should say battles, it never seems to stop. That's a slight exaggeration because there are times when the action slows down and some confrontations are small scale rather than large scale, but it is relentless at times.
That said, I really like where the series is when the book ends. I feel like the ship that is the Dresden Files was thrown into a complete stop at the end of Changes, that it was wallowing and slightly adrift in Ghost Story, then slowly starting to move in a new direction in Cold Days and then it picked up speed in Skin Game, but with some old issues still holding it from reaching full speed. Even with things Harry goes through in BG, I feel like the series is back up to full speed. This is in spite of the fact that in the next book Harry will have to deal with the fallout that BG created.
So could BG have been better? Yes, I felt it was somewhat uneven but it still managed to accomplish important goals from the greater story arc perspective.