Good on you, man! I tried printing through Amazon a while back, and have a whole Twitter thread dedicated to cataloguing my woes. After all the reedits my book came out looking like pure ass, decided to stick with Comix Well Spring since I didn't have the time or energy to mess with it anymore. The only thing I did was make my comic available via Kindle since that was less of a hassle.
It's nice to see when folks get decent looking books from Amazon, in spite of their truly garbage system.