I've done a basic reset and a factory reset and I still notice some ghosting. I've contacted Kobo for a replacement/repair. In case anyone was interested:

The last picture is a bit exaggerated because it's set on 6 pages per refresh. The pictures don't really capture how I perceive the ghosting, which is much more severe. >_>
I've downgraded to 1.9.14 and there is still ghosting.
EDIT: I've taken at some pictures of ghosting and I'm not even sure my problem is ghosting. On closer examination, the problem is very thin and faded outlines of text/images from previous pages. It's almost as if they're block letters that aren't filled in.