why not do it. It is nice to have the option of different focal lengths from time to time. For a once in a lifetime trip, I would bring two cameras just to have a backup. I would only carry one at a time though. For my last big trip I used a Sony NEX with a 24mm prime for 99% of my shots. I only used a zoom for one rooftop series. I enjoyed having the fast fix lens a lot. For my next trip, I plan to use the X100S as my primary camera with a NEX or pocket camera for backup.