I have been playing my current game with this strategy and I definitely feel it's an exploit. Actually, I'm not using the switching-production trick to quell discontent, just to build things fast. All of my cities are tiny, but productive. The reason I feel it's an exploit is that it's obviously counter to the designer's intent. After doing it again and again, fiddling with all the menus you have to fiddle with to get it to work, I realized this was *not* the way the designer wanted me to play the game--if they did, it wouldn't be necessary to do so much wrangling. So I now feel that rushing-and-switching-and-rushing again is something I'll avoid in the future. I'm going to finish my current game with it, but never again.