I don't understand where's the problem.
Compared to reality in which I fly, I never had a simulator with a plane detection modelling so realistic as CoD.
What was unreal were the big dots in 1946, not the way it represents in CoD. Of course I compare to reality, not to another (easier) simulator.
Contacts are difficult to see. Depending on the day, color and background as said, and weather condition. Often, haze mades you only see a plane when it suddenly comes close. Sometimes, a contact you have spotted a second ago disappears from a sudden. I don't mind if the disappearing dots in CoD was considered a bug by many. For me it's not a bug, but a realistic feature.
The only contact easy to see it a big plane, higher than you, in a brigt sunny day.
Anything else, it is very difficult. An I speak on WHITE civillian planes!
I assume camouflaged planes hiding against the terrain is even more difficult to see!!! Did you guys ever flew over a dark plane?