Katoomba is where I always seem to get closest to other aircraft. One time my ADSB picked up an aircraft, even Sydney Centre called out the other aircraft who did not change his path or speed at all. I did both.
Another time a RPT was inbound to Dubbo and it gave me plenty of time to plan and prepare. The radio was my only other means for lookout. Having aircraft appear on my EFB adds to the prep. I still see planes outside the window but more often I see them on my EFB.