I really wish they'd thought about the stadium design properly. AFL / Cricket, poor options to have in a stadium that generally houses rugby and football.
The thing is, when the stadium was being designed and built, ODIs were attracting crowds of 15-20,000 regularly around the country, and it was felt that Wellington was missing out because the Basin doesn't have that kind of capacity. And it seemed a good idea early on, I remember an ODI against Australia in around 2000 or 2001 that drew a close to capacity crowd. You also have to remember that at this time, no-one even contemplated the possibility that Wellington would have a professional football team, A-league didn't even exist back then.
Obviously all of this changed within less than 10 years of the stadium being built, and it's pretty apparent now that what needed to be done is an upgrade of the Basin, and a rectangular stadium at the Westpac site with maybe 20,000 capacity. But hindsight is a wonderful thing, foreseeing how things would turn out when the stadium was being talked about and designed around 1996/1997 would have been almost impossible.