Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.
$46K for a G6ET!! God damn that's good value!
To set a few facts straight...
Yes they both have IRS rear ends. The Ford's CB IRS is not great. The diff bush issues alone are a deal breaker. Having the diff cradle ripped out every service is ridiculous. Up until 2012 (before the revised the design) the diff cradles also tore in half, even in stock cars. They tend to suffer from axle tramp (bit of a lottery), they don't like putting power down, there's no predictability in the rear end- when it goes, it goes quickly and without warning. Overall, not a nice setup. The AU's IRS was nicer, apparently the CB IRS concept was originally designed for front drive applications. VE/F's rear end is on another level.
Meh I've never been one to worry about the interior.