Post war re assessments downplayed the raid as a largely propaganda victory pointing out that the Germans rebuilt the damage done in only 5 months. Dan Snow in his 2013 BBC article restores the balance. The raid did huge damage, in particular pulling resources from the construction of Normandy coastline defences. The propaganda boost was huge, not least in demonstrating the sheer ingenuity and flying skill required. Worth watching just for the sound of those Rolls Royce engines and the final shot of the restored Lancaster.