[Grimulkan]

After some tinkering around, I found that you could actually explode a CBR (or PDF) file into a bunch of jpegs and then embed those jpegs in an HTML. You could tuck all the images away an in a "_xxx" folder (folders whose names start with an underscore do not appear in the DR browser) and then open the HTML file with FBReader.

This is actually surprisingly fast, although I am yet to attempt this for extremely large documents. The trouble is formatting the HTML file right, as you need to get all the images to the right size etc. HTML viewers are also built slightly differently from PDF viewers and are meant to "flow", but that might be an advantage depending on your taste.

You still need to auto-generate a properly formatted HTML file from a PDFs (or CBRs), and I had a script do that. A hastle yes, but I am merely pointing out a possible alternative, given that a CBR viewer hasn't yet come into existence.

EDIT: I just tried this out with a 15MB (50 odd page) comic, and its breathtakingly snappy with FBReader!