Iim not an expert but isn't the pilot seated extremely far to the front; barely any space left for radar or avionics! Or perhaps this is just a technical demonstrator/evaluator, never ment to go into production as a combat aircraft?
What are you talking about? Take a lot at the size of J-20's nose. More than enough room for radar or avionics. Although I agree that the current prototype probably didn't carry one since it is still in the prototype stage.