I bought Savage Empire when it came out. It was... decent. Not great, but not the worst thing I've ever read. The main character was effectively his GAF persona. There are points where you'll be reading the book and, because we're all so familiar with his antics, it pulls you back and makes you say, "yeah, you can tell Bish wrote this..."
I have no idea how it would read if I had no idea who the author was or if I didn't have a generally negative taste for him.
The art and coloring is somewhat uneven, which reflects the apparent struggle with getting the art finished and such.
Overall I'd give it a 7/10, if I'm feeling generous. More like a 6.5/10. There is nothing in the book that makes it a compelling page turner or anything. It tries to be mostly a fun action romp, but it doesn't really build up much drama or significant character development.