Hey OP,
I've been in Australia five years now - I'm not in one of the 'usual' cities, though. It's taken me all this time to feel at home ... but I don't regret a single minute.
Money-wise, the exchange rate has really skewed against the Pound in recent years, so if you are transferring money you won't get a great rate like previously...
And then the cost of living is indeed high, however, housing is so much cheaper (in my experience, though that seems to be contrary to others and I guess it depends from where in the UK you come out from) so it can balance out.
Lifestyle is second to none - beaches, wineries, walks, great lifestyle for children - and there are many more "liveable" days per year than in the UK; lots of sunshine and space.
Not sure about education - all I know is that many more children are privately educated out here because it's much cheaper than UK.
Jobs are pretty easy to get - Australia is riding out the GFC much better than many other Western countries.
But like other posters have said, please consider carefully your reasons for leaving, and that there are enough pull rather than push factors. I came here with "Aus is great, UK is rubbish" attitude, and have had to adjust to the rubbish bits of Aus (racism etc, distance from home, particularly when you need to get back and can't) and missing the great bits about UK (including, but not limited, to: family/friends, proximity to other places, sense of personal history)
I would also say to make sure it's what you both really want - please don't underestimate the importance of that. This wasn't an issue in my case but I have seen it be an issue for too many expats for it not to be a critical factor.
Much of it I would say comes down to personal attitude and determination to make the move a success.
Check out seek.com.au / careerone.com.au / realestate.com.au to do some comparisons of wages/housing costs.
Please feel free to PM me if you like.