After some experience with the new "dots", I think it needs to be adjusted in some way.
First I see the "big" dot at some 6 miles. Fine, that could make it easier to find a fight. However, as the bogey gets closer, the big dot changes into a barely visible small dot which can be invisible depending on the lighting. Then, when closer still, the icon appears.
The problem is that it can be very difficult to tell whether the big dot disappeared because the bogey got closer -- or got farther away. So, I sometimes find myself chasing a dot that can be 6+ miles away and is going the other direction. Also, it is counter-intuitive to see a "big" dot at distance and a much smaller dot closer. It is something that can be learned, but may confuse new players.
(I am playing at 2560x1440 resolution with 4096 texture.)