Dual or Hard tail for rides like GDBR

Getting ready to pass my stumpjumper hardtail on to my teenage "testosterone factory" and salivating over the choices for 29er's out there. I'm dreamin' of TD in 2011 (40th year here) and want to pick the forums brain as to the pro's/con's of 29er's available. I know there are a ton of choices from small shops to the big names but I'm really curious to see if anyone out there has done one of these epic rides on both a hard tail and a dual suspension. If so, which worked out better for you. Most of my riding is in the Gulf Coast of TX and then venturing over to Big Bend, Terlingua, and the hill country surrounding Austin. That being said my heart and unwillingness to let go of my youthful adventure draws me to the Great Divide Trail.

Thanks in advance for any advice.