The LW guys must get tired of having a nice 25k bounce thrown away by the the dot dar, yes? Come down in your Fw190 and the Spit breaks hard at 500 yards, even though he never would have seen you otherwise. You like that?
Dive on a F6F in your A6M5, and he sees this red dot coming in on his 6, and points his nose down and extends away, cool. That must be great. Oh ya, try and escape in a slower fighter too, not going to happen, because even though you outmanuevered them, and they lost sight of you, him and his 3 wingmen just hit "esc", and now they are coming back...knowing exactly where you are. Neeto.
Bar dar represents the kind of generalised info that would be attained from WW2 era GCI stations more than adequately. It gives indications of friend and foe, as well as the rough strengths. In the Vietnam War the USAF fighters didnt have info as good as we get with dot dar inflight. Perhaps today, with digital data links some of the most modern fighters can get something like it, like ADV Tornado or F-14D.
Dot dar, updated like an awacs is a big crutch. Thats why they have it in the MA. For the kiddies.
Later.