Definitely would like to hear this question answered by someone from Outernet. It seems pretty similar. However, I’m going to jump to support which ever service is more focused on neutrality.
They are two different, non-competing projects. Project Loon will provide regular internet service–and do so for a fee (which is perfectly reasonable, considering that 60,000 balloons is going to cost a lot of money).
Outernet is tackling a different problem, one related to information access. By creating a broadcast, one-to-many system, we can provide global coverage at a relatively reasonable cost.