I take the point of this and I'm not saying it would stop me going to a game or that I don't support the concept of a stadium in Petone (I'm still on the fence) but how many intersections do you have to cross to get from either of those two stations to the Petone Rec? In the case of Petone it's about 11 and one of them is State Highway 2. So, while in distance it might be similar, in time it would be colossally more inconvenient.
On a serious note I think the walk is a bit of a red herring anyway. I live in Island Bay and if the stadium's in Petone I will be taking the opportunity to go via Jackson Street and make a bit more of an afternoon of it, get a bite to eat, have a beer etc so the distance direct from either station becomes irrelevant. I know people already go to the Backbencher or other pubs near Westpac but Jackson Street has much more of a village type of feel to it and is literally right next to the proposed location.
I think Jackson Street is a real plus point in this proposal and will probably only get better if this actually happens. On a match day you can imagine Jackson Street really humming, with all the fans larging it up in a relatively small area. The hospitality industry on Jackson Street must be rubbing their hands together already.