"Was the good old pacific fighters less historically authentic?"
Yes, Jason has stated and it is well known that the Japanese aircraft had instruments missing, etc. I'm not sure about the US aircraft, but I expect them to be more accurate as more information is readily available.
"Was it largely based on fantasy?"
No, the maps like Okinawa, Midway, etc were based off the real locations. However, the aircraft and theatre of war would receive much more justice in detail and accuracy, like real sea physics, beautiful cockpits and external models with 1CGS.
I have a feeling many pe