Cool. I'm not personally bothered by cross-genre stories, it's actually something of a plus in my book.
You both are making me really want to check Under the Dome out (I already wanted Horns) and the size of the thing has terrified me, too. Checking it out on Audible is...an intereting propistion
The surprising thing about the Audible download is that it's only one credit. Most audio books of that size and price are two credits. If you haven't taken advantage of one of those free audio book offers that a lot of podcasts advertise, "Under the Dome" would be the perfect one to choose.