Re: Technological edges
The Bf109, Spitfire and Hurricane were all similar in ability. Each had advantages and disadvantages. The Germans had cannon, which was probably their biggest plus - something the RAF didn't get in numbers until later.
If you read about the air war in Europe advantage would swinging around wildly for the next couple of years. Both sides would make a new version of their plane, chuck it into service and give the enemy a nasty surprise when it could suddenly do things they'd learned weren't possible.