Are you still allowing for the kanalkampf period? Otherwise the RAF takes longer to absorb the tactics required to deal with the Luftwaffe. The biggest problem faced by the RAF would be the early models of Spitfire, which were designed to be short ranged interceptors, a role that made them perfect for the BoB, but lousy for taking the offensive to the enemy. If memory serves, this wasn't totally rectified until the advent of the Mk V in 42. So, its possible that the RAF would actually benefit from getting the Mk V at a much earlier date.
Morale wise, the British people loose an important victory with all the possible ramifications thereof.