amit: Outpost Camp is better in all respects but one: you are farther from the summit.
However, it has many advantages: In the trees, not as cold, lower elevation allows may mean less altitude sickness. If you just get up earlier it is certainly possible to make the summit. Leaving Outpost at 6 AM should put you at Trail Camp at 8 AM, and Trail Crest at 10 or 11.
And finally, you don't have to carry your gear so high on the mountain.
