I think my view of banteng has been distorted by Marwell being my childhood zoo and therefore I've probably seen more banteng than domestic cows - gaur on the other hand have always eluded me at Whipsnade, despite my 5 visits over the past decade.
It's a real annoyance to me that the gaur population in Europe was more than just stable but incredibly healthy, mostly due to breeding at Whipsnade and in Berlin, and the plug was randomly pulled to focus on the already more prevalent banteng. Whipsnade certainly has what I would call the best gaur exhibit in husbandry terms, and it is a shame such a large paddock has only 3 females (and breeding age females to rub it in!). So should more bulls be shared I would be amazed if Whipsnade wasn't top of the list; having done a wee bit more research, only Zlin, Berlin, Caberceno, Obterre and Paris hold more than one individual and with Berlin now gaining a bull only Whipsnade is without a male. To rub even more salt in the wound, all the other mentioned zoos have at least 2 bulls each. Therefore...maybe we increase the excitement from a simmer to something slightly more lively.