Mike Irwin, I have to disagree...
... the Germans did have significant fear of our artillery, as well as our armor - even though their equipment was superior to ours.
They really feared our trucks and jeeps even more.
The reason they feared our gear was not that it was better, on an individual level - it's that there was so much more of it, and much faster resupply to keep our numeric superiority going strong.
The Germans had better artillery, but couldn't make enough ordnance for it.
The Germans had much better tanks, but couldn't keep them in fuel or spare parts.
The Germans had better aircraft, at first; even later in the war, their planes didn't give up much to the P-51 or P-47. But they couldn't make enough, as the war went on.
And most of their supply lines, once off trains, were run via horse-drawn carts. They simply didn't have enough trucks.
More powerful or better doesn't help if there just isn't enough of it.
The Germans were not awed by the quality of our artillery, but you can read any number of interviews where German officers said they were in awe of the sheer volume of shelling our forces could keep raining down on them.