The larger stadium works well for games against marquee teams but what about the likes of the Titans, Knights and Dragons, especially in the middle of winter?
Commercially, a shift carries a large financial risk for the Warriors. They earn $1 million-$2 million annually from corporate boxes and lounges at Mt Smart - at Eden Park, there is currently no similar income stream, as the Eden Park Trust Board runs those facilities.
The Warriors also have favourable signage deals at Mt Smart - there is no equivalent at Eden Park - and generate revenue from match-day catering and food sales. These are all negotiating points of any future deal but the starting point for the Warriors is a long way back.
To cover the increased costs, ticket prices would probably rise. It changes things for the average league fan in terms of price, travel to the match and game-day experience.
A shift also defies economic logic. The club averaged just over 14,000 at Mt Smart last year, with one sellout (against the Storm). Capacity may be larger at Eden Park but so are costs. The Warriors, as the anchor tenant, have favourable terms at Mt Smart. It costs them 100-150 per cent more to stage games at Eden Park.
"They are not consistently selling out Mt Smart, which is a smaller, cheaper venue," said one sports industry expert who did not want to be named. "So why would you move to a bigger, much more expensive venue? Unless it's the deal of the century - in commercial terms - it just doesn't make sense."
The sellout of the Auckland Nines has raised hopes a move could be successful but there are crucial differences. The nines has scarcity - once a year, a unique product, featuring all 16 NRL teams - so demand exceeds supply.
Comparing the appeal of a regular season NRL game to the annual nines makes as much sense as comparing a Warriors clash with a Rolling Stones concert. There is also a substantial footballing risk to move. Forget the supposed Eden Park hoodoo, which was based on just a few games and ended emphatically against the Raiders last night.
However, there's no doubt Australian teams don't enjoy playing at Mt Smart and two thirds of all Warriors wins have come there. It's not quite Leichhardt or Brookvale but it can be a formidable venue, especially with the close proximity of the crowd. In contrast, Eden Park feels like any other big-city stadium and is devoid of atmosphere when anything less than near capacity.
The Warriors need atmosphere. Probably more than any other New Zealand professional sporting outfit, the Warriors feed off the environment created by their loyal fans.
The passionate crowd has often been the difference in close matches. Think of the narrow wins over the Sea Eagles, Broncos and Storm last year. Would the result have been different at Eden Park?
At Mt Smart, the fans are almost on top of the players. At Eden Park, the closest fans in the main stand would need a Shaun Johnson spiral punt to reach them.
It's simple maths. If the Warriors attract more than 15,000 spectators to Penrose the ground is about three-quarters full and humming. An equivalent figure at Eden Park is closer to 34,000, which the Warriors have achieved on two occasions, but both came in one-off matches.
Home turf is critical to the Warriors. The Blues have several away games just a bus ride or short flight away, while Sydney NRL clubs can spend weeks not leaving the city but the Warriors cross the Tasman every other week.
The Warriors are not rushing towards Eden Park. As chief executive Wayne Scurrah repeatedly states, "the commercial terms have to be right".
They retain a lease at Mt Smart until the end of 2018 so the onus is also on the Auckland council and Regional Facilities Auckland to come up with an attractive proposition.
As much as the club has been testing Eden Park this year with three games, the next eight home games are seen as a test for Mt Smart. If the club can consistently draw in excess of 15,000 to Penrose from now until September, that could add weight to the Mt Smart faction.
"Neither model is perfect nor future proofed," says Scurrah. "At Mt Smart, there is no level of future funding [the council have committed to spending just $15.25 million until 2022, which covers basic maintenance, with nothing left for development or refurbishment] and at Eden Park, there are residential, parking and cost issues, as well as the size and shape of the stadium. It's a real dilemma."
There's also pressure to relocate.
"The bottom line is that Eden Park is New Zealand's premier stadium," RFA chief executive Robert Domm told the Herald on Sunday last year. "[Our] position is that the Warriors should play all of their home games at Eden Park and we hope that happens sooner rather than later. The ultimate objective will be to see Auckland better off through a rugby league team performing at a higher level and bringing in bigger crowds."
"We want to be seen as the church of live sport," said one Eden Park insider, "with many denominations coming here."
Some things make sense about the move. You could see one season ticket that offers access to Blues and Warriors matches (and even the nines) and it's not uncommon for teams worldwide to share municipal stadiums, like Brisbane, Milan, Rome and Sydney. But all those stadiums are rectangular, football-oriented grounds and attending a live match is an incredible experience.
Eden Park, with its regrettable design, one-size-fits-no-one approach, has massive atmosphere issues. In an age when the televised product is getting better, it has never been harder to drag fans from armchair to grandstand.
That issue is only going to increase with time, which is why there is a growing worldwide trend for boutique stadiums, and makes the challenge of filling Eden Park an ongoing issue.
