One point about the Surly is that you can run wide tires on it. That's great if it's something you think you will need but on the tours I have done I've had no need for wide tires. Occasionally you'll run into road construction or a detour that could be gravel for a short distance but not enough to require wide tires. On tours that need wide tires, like the Mickelsen trail in S. Dakota, I use my mountain bike with light trail tires.

Also, I have no desire to add weight to my bike so I don't load it down with unnecessary stuff. When I do need extras I use my Camelback which holds everything I need.