I've just started reading new 52 Batwoman and I enjoy the story and I love the art but my only frustration/complaint is why is it only 15 pages? Why's it so short? Does this annoy anyone else?

Also with the new creative change do you think the book will be longer?

Are you reading digitally? I ask because BW has more 2 page spreads than any other comic out today (IMO). So, the book actually is the full 22 pages, but it seems short if you look at digital page count because many of those pages are spreads.

Pretty much this. J.H. Williams and Trevor McCarthy tend to spread out action across two pages more frequently than other artists. So in a digital comic, a Batwoman issue will likely appear shorter than your typical comic where most of the pages are self-contained and don't bleed into the adjacent page.