Despite the cost of health insurance (almost certainly covered in full for FAA employees and their families), I'm amused by Brian81's mention of "extra cost of living" (sorry Bri!).
Houses? Way cheaper than UK, especially now with the market crashing.
Cars? Even the new Jag XF, made in the UK, costs substantially less in the US. The Opel/Vauxhall Astra is now sold as a Saturn in the US, at about 2/3 of the British price.
Groceries? About the same.
Taxes? Lower in the US.
Petrol/gas? A whole $3+ a gallon - and Americans find that extortionate! Admittedly, the US gallon is smaller (3.8 litres, Imperial gallon is 4.546 litres), but it's still about 1/3 of the cost in the UK!
Holidays? Great if you like Mexico or Florida for sun, Colorado for skiing!
Things that would hurt? Few decent pubs, greater risk of being a murder victim (though other violent crimes are probably more prevalent in the UK), less leave, dreadful currency if you want to take holidays overseas, Fox "News".
Not that any of the above matters anyway since they're unlikely to open to floodgates to foreigners. I'd be willing to bet that if they did, they would get far more CVs than the Australians could ever dream of!