Beware ! The 457 visa is a big black mark on your CV.....yes I know 457s 'can' work just like everyone else, and that you 'can' switch employers while on a 457, but be warned - employers ask for your nationality and residency status on their application forms, and if you're a 457 you automatically go to the bottom of the list. They MUST demonstrate that they are unable to find your skill set in a suitable Australian in order to hire you. It also means that if your company loses contracts etc or sees a downturn - guess who's nearest the door ?
We came here on a 457 because my ex-employer said they were expecting rapid expansion in the market. it didn't happen. My wife paid $20k for a course of study - which took her 9 months of hard yakka - to qualify herself for an Australian public sector job, then Queensland sacked 5000 people, flooding the market with Australians. On a 457, she cannot compete. Now we find ourselves on the countdown to departure. My wife's qualification, naturally, does not qualify her to work in the UK.....without another $$$$$ course of study ker-ching thanks very much.
If you're in a stable situation and happy with your work, and you're offered a position in Oz on a 457.....beware. Insist on a company-sponsored PR visa, and if refused ask them why - does it smell like a good reason, or were they trying to bring you over for the short term ? If they will only offer a 457, demand that they commit in writing to sponsoring you for PR after 2 years if you are still with them - no quibble. If they refuse, it's a stitch-up. If it doesn't work out, you're at the back of the jobs queue, and on a 90-day clock, at the end of which it's "thanks for all your work now **** off"........