I would not go on long tours on any XT stuff built in the last ten years (see comment above regarding XT moving towards racing). I would not go to a 2nd or 3rd world country with anything but a square taper BB (replacements will be impossible to find), which also pretty much nixes most of what Shimano has made in the last 10 years. Trying to save 200 grams of crank weight on a bike loaded to 70 lbs of touring gear makes no sense to me. Steel chain rings will last longer too, if you can find the appropriate size.