examples/evolConf.txt with 10 Generations took 14s native and 16s virtualbox, and here is what happens for the visualizer (it seemed to me like native was a bit faster without screencast recording):
http://stuff.titus-c.ch/robogen-vbox.avi
@loshchil was right, vbox isn't that bad! Of course, a similar check on windows and mac would make sense before jumping to conclusions.