I have no experience with 29 wheels. I toured last summer on a rails to trails route and while on that trip I decided I wanted a fatter tire than the 37mm wide tires that fit on my 700c LHT (with fenders, which limited tire size options) and decided to build up a 26 inch touring bike. On expendable items like tires, I prefer to use a size that gives a lot of options and there are more tire options for 26 inch wheels than for 29er wheels.