iPhone on Optus or Vodafone in Australia

Hi, I am about to get an iPhone but just wanted to see how people found the Optus and Vodafone networks in Melbourne Australia for both internet and calls? I am leaning towards an Optus $49 cap plan and paying the extra handset costs for a 16gb iPhone because it is better value but just wanted to see what others had to say.

Thanks for your help.

I really wish that I could help you. But, Im located in Michigan, United States. So that is a little ways from Australia. Definatly don't know what the cellphone reception is like down under.