I understand the sentiment from NSW and Qlders in this thread, it is your game and there's every reason for you wanting to play it in RL heartland. BUT, I think playing Origin down here is a massive boost for the code. should be another 50k at Etihad tonight, which is just massive for a sport that supposedly doesn't rate down here. The media jumps on board as well giving the sport promotion - it actually made the back page of the Herald Sun today.
There's also the aspect that says that having a neutral venue each year is the fairest way to decide who the better team is in any given year. Each side gets a home, away and neutral match, meaning there's no unfair advantage to the side that gets two home matches a year.
Above all though, it's great for people like myself who would never get to go to origin. I went 4 years ago at the Dome and the atmosphere was electric, and the footy was brilliant as well. If there's 10k RL first-timers at Etihad tonight, then there's every chance that those people will attend another RL match in Melbourne, as after all, SOO is a great product to sell to newbies.
All in all, I think it's brilliant for expanding the code... fair call by those saying we should just have Kangaroos matches down here instead, but everyone knows that Origin carries more hype, even for neutral states.
