I put this together yesterday, with help from the ten winning teams. It's kind of like the occasional HN post that looks at hosting decisions made by YC companies. Maybe I'm just a gems geek, but I find this sort of thing fascinating.
I would also throw out that the Rumble provided a server setup script that automatically used Capistrano and MySQL, so it would hurt your time a little had you not used what they provided. That may have skewed the deploy/database usage results a bit. The only reason I used MySQL was that I essentially got it for free through the setup script.