I've only ever owned 26"ers, but I've demo'ed a couple of 29"ers. One of my favorite trails can actually be rocked quite nicer with a 29"er than with a regular MTB. If I don't buy a new road bike this year, I will probably build up a light rigid-forked, fat-tired, geared 29er. No way would I get rid of my 26" Stumpy hardtail. My other favorite trails are twisty and technical and I'm way too used doing them on 26' wheels. Old habits die hard.