As I mentioned in my original post, there are roaches everywhere in the world, but the ones I encountered in Japan were bigger and more plentiful. Nothing in my experience since returning has changed that perception. In fact, since coming home, and living in three different places and two different states, I haven't seen one roach. Of course, I haven't hung out in many seedy dives or back alleys full of dumpsters, but there are dumpsters in my current apartment complex with nary a roach in sight. The fact that I have not seen roach motels or special roach killing spray prominently displayed in stores in the summer (which was always the case in Tokyo) supports the idea that it's just not that big a problem here.
The weather in Tokyo as well as the close proximity of people meant that roaches were something I was never going to escape no matter how clean I kept my place or how trash was managed. I absolutely am happy not to have to deal with them anymore.