It seems that it would be way too easy to "outspin" a 50 x 34 chainring setup on typical terrain. While my current arrangement is a standard 53 x 39, if I lived in the Rocky Mountains and rode there all the time it might make sense to have a triple for a true "bailout" gear. The cross-chaining problems have been mentioned very frequently. I think that a double should work for an overwhelmingly large percentage or riders.