That the Germans had superior technology is no mystery to this child of the 60s. My brothers and I would build Revell and other plastic models of Allied and Axis weapons. When we weren't blowing them up with firecrackers, we would zoom around the house in mock combat.
I played Allied, and loved the P-40, which my brothers would always shoot down with their ME-262s or their German AA guns. And I remember seeing Patton in the theatres and coming away with more respect for Allied soldiers that had to fight superior weapons with guts and numbers and not much else.
At Kasserine, El Guettar, in Sicily, at Salerno, in Caretan, Lehr in front of St. Lo, Mortain, the early Lorraine fights culminating in Arracourt, the Bulge, and Alsace. In the largest of these, the Bulge, the US lost 2 divisions. In Kasserine it was 2 regiments. In most it was more like 2 battalions, and in all cases these initial losses were 2 echelon levels smaller than the German attacking force.
And those were inflicted precisely by having better odds (especially in armor) at the initial point of attack. As soon as US reserves arrived and redressed that, the Germans started losing. Read in particular the story of US third army in Lorraine in September, in Hugh Cole's "Lorraine Campaign" (one of the US army "greenbooks", the official history).
The Germans did have pro officers, excellent infantry that fought very hard, and superior tanks. But they had very stupid high command, an overly aggressive doctrine that threw away their armor on fruitless counterattacks, and not much in the way of mobility as an entire force. (80% of the army was rail and horse dependent). On the east front their "play" in pure military "chess" terms was quite poor from the autumn of 1942 on, with only passages of brilliance. Anyone who can read a map can see the Russians made better moves at the top level.
Also, the Russians beat them in the home front stuff on their own. From the same industrial base prewar and under far worse conditions (the Germans took 40% of the country's population and industry), they outproduced the Germans 2:1 in tanks. The reason is the Germans were so arrogant after their early cheap victories over lesser opponents, they didn't bother to mobilize their economy when they attacked Russia. This is one of the great world historical blunders. And that one was entirely an "own goal", pride as a weakness.