I went Telstra. Absolutely seamless and pain free in the installation and the service is reliable. You will pay more tha for Optus, but there have been absolutely no problems for me from day 1 and they event trialled me on some new technology for a few months on new high speed fixed wireless setup which was good.
Optus were bloody hopeless and every time I rang them to find out where they were, they told me that my appointment had been cancelled mysteriously.

