[drcoastline]

If my memory is correct the mustang wasn't originally powered by the Merlin and was an under performer. It wasn't until it was in theater that the Merlin was installed and the Mustang came to life. I think after that the Mustang was a better performer all around.

Mustang v. Spitfire I think the mustang wins more often than it looses. As I recall it won more often than it lost in real battle. Granted it over whelmed it's opponents by numbers but think it was still superior to it's adversaries in many ways.