I'm 6'4" and 260. I tried out a 26" and a 29er. With the 26 I always felt like I was going to go over the bars while just riding. I could have maybe put on a longer stem but that may have shifted my weight enough forward so that I would go over the bars. With the 29er I am very comfortable. I haven't done much off road with it yet though.

As always ride a few and see what you like!

Bill