It seems that Beauval's bird show is its main asset.
I'm going to open a dangerous discussion here, but let's talk about the welfare of the birds in the show. I'm not overly familiar with this particular show, but I've seen enough and I've talked to enough people to know that birds in flight shows are often - very often - housed in terribly small avairies outside show times, if they aren't confined to a single branch that is. We're talking about dozens of birds ranging from kites to macaws to cranes to ibises. Large birds with complex behaviours that need behavioural enrichment and adequate space throughout the day, and not just for an hour.
I don't know the situation in Beauval, for all I know they have a huge avairy and they simply open the door and let the birds fly out willingly (as Avifauna in the Netherland has). But I think that knowledge is crucial for rating this bird show. Usually, I would give the benefit of the doubt about animal welfare. Who am I to judge? But I've seen it go wrong in bird shows so often, that this time I just can't do that.
I accept that I put myself on a slippery slope here. But if the birds are housed in a "traditional" way - small, barren enclosures - , only for the spectacle of having even more birds in the air, then that's not justified in my opinion. I truly hope I'm proven wrong.
On a more positive note, the hippo avairy looks downright fantastic, at least for the birds.
Yep, that's a thing I was considering as well. When you're sitting there looking at the bird show it's fantastic, but then you look behind the amphitheatre and see
this, a row of 6-7 smallish seriema aviaries (6 pictured, I believe there was a slightly bigger one to the right of this picture as well that also had some parrots)... I don't want to make claims about the other holdings that aren't visible to the general public though, but I agree with the general tone of your concerns.
While impressive, the show is also
very chaotic with many birds ending up all over the place and just walking around between guests, or birds of prey walking among birds that in wild settings might otherwise be considered prey... I can imagine such a thing is very stressful, and I also imagine escapees among the harder-to-train birds have to occur fairly frequently.
For the rest, I'm confused about
@amur leopard 's post claiming there to be "3-4 massive greenhouses just for birds". On my visit there was the one close to the entrance that would definitely count and is mainly a bird house, but that was it... The other tropical houses (one for apes and reptiles, and one for gorillas and manatees) barely held any relevant bird collections at all.
The bird house close to the entrance and the bird collection in the hippo aviary are definitely very impressive, however.
All things considered, I don't personally think Beauval can compare to Bronx with its amazing World of Birds, which has to be one of the nicest and largest bird houses in the world anywhere... I don't have the time myself (exam tomorrow...) but I hope somebody can illustrate this further.