I run my 29er as a 2x8 and I really like it. My 24t front chainring is pretty much all I ever need for singletrack, and I go up to the 34 for roads. I would need a pretty epic tailwind, downhill, to need more than the 34. That said, I run a higher cadence than most. For some reason my bike has a really direct chain line from most of the cassette in first gear, there are only 2 that I really can't use. Not sure why that happened in this particular case.
I replaced the third chainring with this bashguard:
http://www.amazon.com/Nashbar-Mountain-Bike-Bashguard-110MM/dp/B004UMEFA0/ref=sr_1_2?ie=UTF8&qid=1398804292&sr=8-2&keywords=nashbar+bash+guardNot the lightest, but cheap. Bought it with a new second chainring after I busted it in two rides.