German quality was largely a myth. Examine tanks; they need to be survivable, reliable, and potent. Without all three, they're useless. German tanks were rarely the best on the battlefield when measured this way.
Aircraft (especially fighters) have the same three requirements: until the ME-262 was deployed, Germany was only on par with the allies.
Artillery? Other than the feared 88mm, its artillery was clearly second fiddle to the Allies.
What enabled Germany to have any success was the initial training of its NCOs and officer corp. This allowed them to exploit opportunities faster than their opponents (think of Boyd's OODA cycle).
But all the oft-touted German "super-weapons" were usually over-engineered stuff that didn't work reliably. Note that the ME-109 flew until the end of the war since it was reliable, and effective against bombers until they were escorted by Mustangs and Thunderbolts.