Having lived in both countries (Can/Oz) I guess I can weigh in on the merits of both systems:

1) You can have unlimited mobile calling in Oz, especially through voip: www.gotalk.com.au - or search on google for go talk unlimited voip calling plan (it's technically 1000 minutes, but nearly unlimited)

2) I bought PAYG in Canada as well as PAYG in Oz. $20 of PAYG seemed to barely last me a week because of the fact that the incoming calls were charged, I found myself trying to get the other person to say what they wanted as quick as possible so I could cut my call costs down, that's despite the fact that the PAYG plan including unlimited evenings and weekends for only $1/day! In Oz on the other hand, with a $30 "cap" plan my credit lasts for the entire month, even when people call me for hours/or I call them. I find myself a few hour long conversations during the month and I'm not afraid when people call me as I know the call will be free to me. You are right however, I get fewer people calling me from a landline, with the majority of calls being from other people's mobiles.

3) There is a new plan from Telstra - called the Get connected plan which is probalby the best plan I have ever seen (North America included) Basically the details are $40/month, no call credit though, but 1) unlimited incoming minutes 2) only 0.35c/call (no per minute charges) to any landline in Australia 0.35c to any Telstra mobile in the country, and .36c/minute to any other mobile. However very few people have even heard of this plan, so my guess is that North American style pricing is not that popular in Oz.

4) People in Oz tend to be more mobile than North Americans. I have noticed quite a few people making calls to other states even countries on their mobile, more frequently than in Canada anyway. I knew of almost no one who would dream of making a long distance call on their mobile. Most would turn of their mobile during the day, and just using the unlimited evenings/weekends. So in that sense the "pool" of minutes in a few of the mobile plans in Canada are for local minutes only - long distance is still billed seperately, and usually at pretty high rates. Though I guess that's changing as well. Also in plans where incoming is free, that is only for local calls, again if someone from the US where to call you, that would not count.

5) Texting is more popular by far in Oz than in Canada. Probalby because of the relatively low call rates to Mobiles in Can vs. Oz. However now that I've gotten used to the texting I find it does have it's advantages. For example if you're on a bus it's pretty rude to be having a conversation on your cell, and that's the perfect occasion to be texting back and forth with your friends. During the day time, being in an office/school etc. texting is also easier as it disrupts less people.

So my final point is that each system is really designed for the use of the people in that country.