I have not backed this Kickstarter yet. I am undecided as to whether I will. I also agree that three free dcs level aircraft is to many. I think non backers should get to choose one of the three release aircraft.
I do think however that the one free aircraft should be a fully capable fighter if you want to attract new blood into the hardcore flight sim genre. Rise of flight gives away one free fighter and it has worked well for that game. I would suggest that you get the three aircraft only if you back at the $40 or above pledge level.