Auckland should follow similarly sized cities such as Adelaide and Perth and adopt a two-stadium strategy, says one of Australia's most experienced stadium architects.
Alastair Richardson has worked on Wellington's Westpac Stadium, Dunedin's Forsyth Barr Stadium and several award winning stadiums in Australia, including Adelaide Oval and Suncorp Stadium.
He was in the thick of Auckland's waterfront stadium debate in 2006, which he believed was a great idea but too risky in terms of being completed for the 2011 Rugby World Cup.
Ten years on and the national director of Cox Architecture in Melbourne fully supports the latest push for a downtown stadium.
Mr Richardson believes a dedicated rugby stadium is the right call within the CBD, with a capacity of 45,000 to 50,000 and the ability to expand to 55,000 to 60,000 seats.
He said Auckland also needed an oval ground for cricket, suggesting a boutique venue for about 20,000 spectators was about right.
The two-stadium strategy, he said, was used in Adelaide and Perth, though in those cases the major stadium was oval for Australian rules and cricket with a smaller, 20,000-seat rectangular stadium for football, league and rugby.
Even Melbourne - population 4.5 million - has pursued a rationalisation of stadiums and settled on three: the Melbourne Cricket Ground, multi-purpose Etihad and AAMI for football, league and rugby.
Auckland's stadium strategy is still a work in progress. Mr Richardson said Auckland planners should look to the development of the 50,000-seat Adelaide Oval.
"The A$535 million ($599 million) development opened in 2014 and has transformed the fan experience and reinvigorated Adelaide's CBD," he said.
"It has dramatically increased average crowd attendances since opening and replacing AMI Park at Westlakes, the former suburban ground that hosted AFL."
His view is shared by sports administrator Martin Snedden, who supports a new downtown stadium in Auckland despite his ties with Eden Park.
"The right kind of stadium can revitalise a city, which is what has happened in Adelaide," he said.
"Since the Adelaide Oval has been revamped the stadium has captured a magic that it hadn't had for a long time. They are getting great attendances to the Big Bash, international cricket and AFL."
He said Melbourne has also taken a "horses for courses" approach. The Melbourne Cricket Ground, Etihad Stadium and AAMI Park fill varying needs, but all are centrally located and well attended.
Responding to a suggestion from Warriors chief executive Jim Doyle that a 30,000- to 40,000-seat stadium could cost $600 million, Mr Richardson said that was at the "upper end of the scale".
It is about the same cost in local currency for the Adelaide Oval and more than the estimated A$300-$350 million for a new 30,000-seat stadium at Parramatta in Sydney.
The 31,000-seat, covered Forsyth Barr Stadium in Dunedin cost about $270 million.
Mr Richardson acknowledged that stadiums were increasingly competing with people watching sport on the television at home.
Those stadiums that provided facilities that people want to go to were easy to get in and out of and offered quality food and a social experience were doing well, he said.
It was also recognised, he said, that stadiums were an important part of a city's civic structure.