I have only been to 4 out of the 7 mentioned.
Wild Place - Absolutely beautiful! Quite a trek to get there, so maybe not great for those who are less mobile, but 100% worth the walk! Interesting having wolves in there as well, although I did not manage to see any. But the cove they have made for public viewing is magical for anyone (zoo nerds or not) to view the species roaming the woodlands.
Wildwood - A little biased as if it wasn't for Covid-19 I'd still be on placement there. No doubt an interesting layout. No way near as large in surface area as Wild Place but has some nice features. I particularly enjoy the body of water they have amongst the greenery, as well as the rope bridge over the top of the exhibit, which is great from a visitor perspective! I have also been able to see their inside quarters and a smaller outdoor area they use for the boys when they go through torpor. It's well designed and partially made from large metal shipping containers - woo recycling!
Whipsnade - An old fashioned bear pit enclosure - understandable as it has been in use for donkeys years, but the naturalistic-looking space is used well! Obviously is not a classic pit, but just has that feel from where the visitor viewing area is mostly raised. I haven't seen the exhibit since the younger bears have been in it, but when they had their geriatric bears, they seemed quite fine with using the natural shelter/shaded areas from the trees. It has a nice viewing experience as one walkway is used for two enclosures (Wolverines/Bears) either side. Inside area was interesting to view also, as keepers have access through mesh to the main enclosure as well as their smaller outdoor area and inside areas.
Welsh Mountain - Quite a lot smaller in comparison to the much newer Wild Place, but it has a lot of character. It seemed they work with what they have, and give their bears enrichment to make up for the lack* in size. Something I noticed more so with Welsh Mountain than any other was their signage. It was very personal to them - for example: enclosure layouts, as well as information regarding their own bear's torpor and diet - to name a couple of factors mentioned on their signs.
*no negative connotations, I still like the enclosure.
All in all, Wild Place has had a lot of money plowed in, but has been worth it. An incredible place.