I brought my road bike. I actually just bought a Surly LHT (but it arrived while I was gone - picts of that in the main discussion thread soon...) - the Bianchi (Eros Donna) did amazingly well. She rode well when loaded up, but was remarkably heavy and a bit tippy behind when I was trying to walk her. If you only check one piece of luggage, you can check a bike for free (for now) on Lufthansa (probably only an international thing). Hauling a big bike case was interesting, but I was really glad to have my own bike that I know well and fit well for any sort of distance.