I, too, visited Dachau in the early 80’s. The profound Spiritual impact I felt that day has never left me. Burned into my soul.
I would say impact is an appropriate description. Like a hammer blow of horror and despair.
I think the camps should be preserved.
I visited Dachau twice during my tours in Germany. I found it very sterile, almost anstiseptic. Most of the camp is gone and it was almost impossible for me to visualize what had occured there.