I agree with six on this, I've toured on a big adventure bike and regularly suffered with back and arse ache, and that was with a gel insert in the saddle, suffered the same with an FJ I had a few years ago. I've been to Switzerland on a fireblade, with the unique discomfort riding a sports bike produces, sure I could load the ADV and FJ up with luggage, but the blade was much more fun on the Swiss twisties with just saddle bags At the end of the day its personal preference and what feels right for you, ask yourself what you intend doing and how much luggage you want to carry, you'll find a story on the net of someone who toured India on a 50cc! Don't expect though, after a day or more in the saddle, not to have aches and pains in some form or another, regardless of what your choice of bike is. The whole ethos of biking is freedom and individualism, choose a good all rounder that feels right for you, load it up and get out there and enjoy it.