The Atom-Bomb could certainly have been an option, if German resistance had continued a few months longer.
Fortunately the Reich surrendered on May the 8th 1945 and there was no need to put nuclear weapons into action against Nazi Germany.
Back to the topic of conventional US Forces of this period I would say that their equipment in most areas was at least adequate.
The American Military usually was better supplied and mantained than their German Adversary and had the advantage
of almost complete Air Superiority. In terms of strategy, tactics and training the Americans were very well advanced.
Please excuse my lousy English!