Beastly Kingdom stoked my imaginagtion more than Avatar does both conceptually and thematically, though I will say that I think what they achieved with Pandora exceeded my expectations on several terms.
I will also say that Blue Sky Concepts that never see the light of day are not subject to budget cuts and the realities of moving a project forward that executed concepts all pass through.
So while I would have been more likely to give Beastly Kingdom the greenlight over Pandora if it had been up to me, I know better than to think that the Beastly Kingdom we talk about is the same Beastly Kingdom that would have actually been built.
That said, given my own personal tastes, interests, and interpretation of Animal Kingdom's theme, I would probably still pick some version of Beastly Kingdom. Ultimately for me it comes down to the timelessness of its theme and the desire to have creatures of that type represented in the tapestry of Animal Kingdom, mixed with my preference for the practical, Animatronic-and-Set-based types of attractions that BK was set on bringing us. So I voted BK.
That said, they really did a bang-up job with Pandora. I'd have to assume the money they spent there far exceeds what would have ever been spent on a Beastly Kingdom, and I think this is a rare case where the guest experience still made out like a bandit if this is what any of us consider a second-choice offering. Regardless of preference, Pandora is for sure the more ambitious of the two projects.