Wow, 30km/h average? That's pretty gangster. I can only DREAM of going at that speed.
To be honest, commuting/riding my steel Cinelli so far has the best returns and gains. It's heavy as fuck so you're forced to just ride and push yourself. And then I get onto the Guru or Cannondale and it's just like -
Average speed up by 3 - 5km/h.