To be honest, I think London's looking better than it has done for quite a while at the moment (Reptile House, Clore (diminished but still good), Aquarium, Blackburn Bird Pavilion, BUGS, new Penguin enclosure all excellent). It would seem that the remaining "blind spots" are known/understood and plans appear to be in action to remedy them over time.
My biggest bugbear when I visit is how much space I perceive is wasted due to Lawns, Merry-go-rounds and non-animal exhibits (and could be freed up for further "charasmatic megafauna") -but I accept London Zoo can never be all things to all people and ultimately I am happy it seems stable and improving.
These are matters of opinion - personally I think the destruction of a third of the Moonlight World to build a rainforest area in the Clore was dreadful. The same effect could have been achieved by linking the ground floor courtyard areas together.
London is not an easy zoo to re-develop; too much history, too many planning restrictions, too many people with a stake on the site. (It would free up a deal of space if the Institute was at Whipsnade, where the land required to house them would be immaterial, rather than at London, where it isn't).
In retrospect, the site had too many large mammals onsite 30 years ago. Elephants, two species of rhino, giraffe, three species of equid, five of big cat, four of bear, three of great ape....it was too much. It was a tragedy that more large mammals weren't moved to Whipsnade in the 1960s when money was available and very little was done there.
But I do feel that more could be done at London; IMO there's space enough to accommodate another species of big cat, and one or two smaller bear species. I also feel that whilst immersion exhibits are fine where you have the space and climate to make them credible, a cramped site dating back to 1828 (when Mexican rule still
had twenty years to run in California!!) isn't an ideal place to try them.
I agree with Shorts about the lawns, and for my money's worth the animal shows take up space that could be better used on other causes. The Snowdon Aviary might usefully be quietly hawked off to someone in the Middle East or American South-West, where the climate would make it work and there are enough people with money to be impressed by its royal connections. And as the father of two and stepfather of three I feel able to say with some certainty that a decent indoor play area (such as can be seen at Woburn) would be more of a draw than "Animal Adventure".
The real challenges are the Elephant House and the Mappins, at present massively underused. Their future use will make a big difference to London's future.
Whilst I agree with a lot of that, the animal shows are really popular with younger visitors - sometimes even the highlight of the day and I would rather they want to return for that than because of an indoor play area.
If I was able to do it, I would net over the mappin terraces and use it to house Australian birds as well as the macropods, with bridges over the moat (if it still exists) and turn it into a walk through exhibit
I would also look at the old elephant house and see if it couldn't be altered to house Orangutans or gibbons with one large outside area revamped with a more naturalistic look. Using the moats for short clawed otters for example. inside could house smaller Asian animals or reptiles to make a more representative display of Asia's animals.
Just my dreaming of course.
I have only been to London zoo once many years ago now and I haven't bothered to go back, sadly London has so much to offer apart from the zoo