The power consumed by the transmitter increases as the channel number increases particularly at high powers. The coverage range is also less for the same radiated power. The losses in cabling is greater. So band 3 is the best compromise for large areas of Australia except where a local repeater is required. Then using the upper end of the UHF band is ok because the total power is small.
We are vacating 45-52, 54-70, 83-108 and 137 - 144 MHz (channels 0-5 & 5A) when analog is switched off.
UHF subjective picture quality is always much better.
When aggregation occured everyone had to buy a UHF antenna, possibly new masthead amplifier and many also got a new VHF aerial because all the old 5/6 regional specials didn't work on the new ABC channel 11 (unless turned sideways! and then they didn't work on Prime 6). So, it would have actually been cheaper for most viewers in regional areas (not just here) if all UHF was organised.
When analogue is switched off here we will have one only VHF digital on channel 12