Problem with dueling is you only learn one small aspect of the game. Main Arena does not play fair, dog fighting is a 3 dimensional. Then again you can climb 20k above everyone else and still suck, this is where DA comes in to learn your basic roots.
My fun has always been pick 2 aircrafts per tour (I rotate aircraft every tour) - I often joke with bone "Pick a plane for me". When you learn the basic/advanced aspects of each aircraft you understand the game far better.
Everyone has their "Rides" I often joked I never had a single one but actually looking back at a year of flying I seem to stick with the Ki-84 - decent Eny, decent plane, underrated. I often will pair it with something else - i.e a Pony or P-38 so I can understand the different styles of flying.
I don't think Dueling ever helped me, or simply flying the MA - Getting involved with FSO, Scenarios, Snapshots, Main Arena and DA is what formed me.