said 11 months, 2 weeks ago:
Facebook’s auto scheduler: I am intuitively inclined to say “no”, but I haven’t seen any research either way.
3rd party apps (e.g. HootSuite): a while back, there was a confirmed loss in EdgeRank. Facebook apparently fixed the problem, but then in April 2012 HubSpot conducted its own internal study and found that posts published via the API have statistically fewer “likes” and a lower CTR (click-through rate).
In short, I’d stick to manual posts as much as possible, followed by scheduled posts from within Facebook, followed by scheduled posts from 3rd party apps.