Hi Super-T. I am located in Australia as well. Let me give you an Australian perspective. We have a Vista HCX and wanted a second GPSr as the son and I tended to get separated from the wife and daughter during hikes and geocaching tips. From Internet research, I was leaning towards the 60CSX as it seems to have less complaints.
However, being a technophile, I feel that not getting the latest gadget is a step backwards. Like yourself, I posted a query on the Geocaching Australia forum and got very good responses from Australian users in favour of the Oregon 300. I decided that I needed to see it for myself to convince myself that the Oregon is usable.
The local shop was kind enough to allow me to take the Oregon out into the sun. I had my HCX with me to compare. I was happy with the accuracy of the Oregon. The screen turned out not to be a problem. In fact, I normally have the backlight off. I only needed the backlight when it gets dark. I did not experience any problems that was described within this forum and am very happy with the unit. Firmware 2.5 that came out last week seemed to have resolved the obvious bugs. Someone came up with a Wherigo cartridge that does waypoint average (very clever).
As had been said before, go and see the unit for yourself before deciding.