I last time I used vagrant was 1.2 on whatever the latest virtualbox at the time was. The performance was about half as good as the host machine. The host machine was running the desktop version of Ubuntu at the time. I was not able to easily identify if VirtualBox's performance problems were CPU or IO bound. If I hear that the performance is close to native, I'll give it another try. Otherwise, I can't see the point.
When I was using vagrant 1.2, lxc containers were not fully functional so I didn't bother trying with lxc. I'll gladly give it another try to see if performance is significantly better than virtalbox. Thanks for the tip by the way.