Heroku cedar: slower response time than bamboo?

I've a rails 3 app, running well/fast on herokus bamboo stack. To test whether my app works on the upcoming cedar stack, I've deployed it to heroku, following the "getting started" guide. To my surprise, everything works well and without an error. The only difference I've noticed: the response time is quite a bit slower compared to the app running on the bamboo stack. Tests with unicorn instead of thin showed no differences.

Have you noticed roughly the same difference between the both stacks?