I have done several cross-country trips with my Hasselblad 503 and 50/80/150 kit as well as an extra A12, several filters, meter and lots of film.
But I recently bought a Mamiya 7II and will be using this for my travel kit from now on. I have the 50 and 65 and I am looking for the 150.
I am with mrcallow. The camera is light and easy to use and I get BIG negatives. And my favorite lens (right now) is the 50mm.