They may have added new channels in between some of the existing channels, but these seem to be for repeater output only.

Yes - older equipment may interfere with some of these, but as I said before, this will be difficult to police. In many areas of Australia, these repeaters will not exist in any case, so not really an issue. Because the new repeaters will be newer equipment and transmitting on the better controlled narrower bandwidth, it is unlikely that the repeater output channels will interfere with the original channels, whether you are receiving on a new 80 channel radio or on an older 40 channel unit.

The fact remains though that the original 40 channel frequencies remain unchanged. I'm not techno savvy and not sure how to post links on here, but if you look at the two tables at the following web addresses, you will see that the frequencies for channels 1 to 40 remain completely unchanged between the old and the new systems.

UHF CB Australia - 40 Channel UHF CB Radio Information & Allocations

http://www.uhfcb.com.au/80-Channel-UHF-Information.php

This discounts the previously claimed theories that the new and the old radios are communicating on different frequencies and some might come out "softer" or "louder" on different radios due to frequency differences. This is simply not the case.

Also, the fact that I use an 80 channel unit daily and regularly communicate with others using both 40 and 80 channel radios tells me from experience that such claims are simply not reflected by what I experience daily.