I like my 34 when in combo with the 26 up front on a steep hill with a touring load. In fact I would say theres no way I'd get up without it some days. Or, I may just be on a night ride and not feel like stressing my knees. As I get older I find that while my cardio and muscles are fine, my knees are not. Muscle up a hill and I'll pay for it for days.