I did warm up the JVMs, actually. Those Rails numbers are far too low for TorqBox. Perhaps the best thing to do is add this to the techempower benchmark suite so a 3rd party can run and present the results.
Since both Jubilee and TorqBox are easy to install, I did a quick test of both on my machine with the TechEmpower JSON app to get a feel for the relative performance - https://gist.github.com/bbrowning/8244516
My laptop gets 19k req/s with Jubilee and 118k req/s with TorqBox on the same Rack app. While Java on Vertx does fare very well in benchmarks, it's incorrect to assume this directly translates to other languages and frameworks written on top of Vertx also having the same high performance.