If one is from a country that has a relatively easy employment visa (e.g. Canada, Australia), is it worth getting an H1B? I know that H1B is dual intent (i.e. lets one apply for a green card). Any other reasons?
It's cheaper, easier to apply for, processed faster, allows heterosexual married spouses to work, is renewable indefinitely, and has a separate annual quota from H1B's (that to my knowledge has so far never been exhausted).
There are a few catches, some technical and quite specific (e.g. limits on international travel). The main one seems to be you will need to leave the country (possibly overseas) every 2 years to apply for an extension.
It is not a dual-intent visa, but there seems to be some contradictions about that and some people seem to have made the transition to a green card. I imagine you'd need to talk to a lawyer about that - having a green card application in progress when it comes times for an E-3 extension would potentially be an issue.