Telstra's NextG has much better coverage and speed... my virgin/optus iPhone comes with 2gb of data per month... which is pretty much useless...
out of sheer frustration i bought one of these...
http://www.telstra.com.au/shop/Consu...&top_category=
i paid $150 for the modem plus 5gb/90days, and have since topped it up 10gb/365days for $150...
coverage and speed are excellent, and not too pricey... keeping in mind that generally you get what you pay for...
i only use it when im away from home and have been really happy with it... i would have it augmented into the back of my neck if the option was available...
if your move is temporary this would still be a good long term option as a backup and mobile hot-spot...