Ask everyone again. This was true a long time ago (long time being, like, 1.5-2 years), where the Facebook app was so slow and so crashy (and the API down so often) that it was mostly useless.
Facebook is, IMO, one of the gold standards now for large-scale iOS app building. I had the pleasure of hearing one of their people speak about this a few weeks ago and they're very much at the forefront of iOS engineering.