Just say no to the Korean War. It's still on so the mig15 vs F15 would get boring 
F-86 Sabre,... and they are a blast. Faster thinking, much wider playing field, steady hands.
Personally though, I love Korea era jets, but if it comes down between updating the main game or adding a different era of war, I'd rather see them get a little further ahead in the main game first. I wouldn't add it thinking it will change much in the game as these seem to be secondary personal preference items....to prop pile-its >>>>IMO.
IMO, someone who is really into to jets they are most likely to be found in another game that does that full tilt with modern models as well. So I don't think it will be a draw to the game for new players. And I don't think existing players are going to see it as a lasting major change.. but hey I could be completely wrong.
I think that concept works the same way for prop lovers. If you want a prop plane you probably will most often fly the better performing WWII models a majority of the time,...then WWI.
Both Korea and WWI are great fun, but IMO the mindsets work against the middle more preferred era. If it were me ( and you all thank cod it's not) I would add something like that when I have a month of pretty much nothing else to do. That said if it's not a big time consuming deal, then give it ALL to us....

Animl