[imiller]

If you go on Oxygen, you basically want to have enough to get you down to camp. The effects of coming off Oxygen can be totally debilitating. There are also advantages to climbing without Oxygen if you have the proper physiology, mainly you don't have to worry about carrying g it or running out. Anatoli Boukreev's book about the 1996 Everest disaster is very insightful. Among other factors climbers running out of Oxygen contributed to the scope of that disaster. It's a fascinating read.