I would not trust predatoryjournals.org. Beside the site looking much like the worst predatory journals, they have no transparency in who they are and how they evaluate journals. It seems just to be Beall's old list, with some newer things thrown in.

I'm not saying that Frontiers in Neuroscience is not predatory, but its not a proper argument for it to be predatory, to point to a random list as proof. As Beall couldn't understand being crap publisher is not predatory in it self.

That's totally fair, and I'm often reminded not to paint all "Frontiers" journals with the same brush (although it's difficult for me sometimes).