Hmmm....I 'get' hardtail 29'ers. They make sense and I've actually owned and raced two Niners in my one and only attempt into the lycra clad XC field. It was pretty much lame and a huge fail on my part, but whatever.... Before I actually pulled up to the mass start line a friend and pro racer said to me that he liked it when guys showed up on

29'ers

because it meant he wouldn't have to worry about trying to out race them.
I also briefly owned a super sweet Turner
Sultan. Turner quality, nice paint, welds...but the thing weighed as much as my 6.5" travel bike built up complete with DH bars/stem/all mountain wheels and a Gravity Retarder. The steep HA and giant wheels were sketchy at best. After a couple months I could not justify a 4 inch travel bike with a ho-hum Reba (this was before Fox released it's 29'er Fjork) that weighed as much as a decent all-mountain bike, cost the same, but offered way less performance and I was truing the wheels after every ride.
So I did a weight comparison of my EX1750's mounted up with 180mm rotors and 2.35 tubbed Minions vs. a pair of Mavic Cross29er wheels mounted up with 160mm rotors and 2.1 Maxxis tubed Ignitors. They weighed the same. Yet I still have my original pair of 3 year old EX1750's which I've only had to do a couple of minor tru's whereas the 29'er wheels were almost falling apart-and I was only doing XC-type riding on them.
Full suspension 29'ers make about as much sense as riding a fixie downhill with 6 inch wide balsa handlebars.