[Manstein took his Prussian heritage seriously, and despite other officers trying to get him to turn against Hitler, he never did. He was loyal to Hitler to the end, even after Hitler fired him, he kept returning to Hitler, even as late as early 1945 offering his services to fight for Hitler. Jan]

This verdict on Manstein actually comes from British sources as best I can make out. It possibly comes from Liddell Hart who was a very important British tank theorist:
The general verdict among the German generals I interrogated in 1945 was that Field-Marshal von Manstein had proved the ablest commander in their Army, and the man they had most desired to become its Commander-in-Chief. It is very clear that he had a superb sense of operational possibilities and equal mastery in the conduct of operations, together with a greater grasp of the potentialities of mechanized forces than any other commander who had not been trained in the tank arm. In sum, he had military genius.

Here are some quotes from Manstein:

There are only four types of officer. First, there are the lazy, stupid ones. Leave them alone, they do no harm…Second, there are the hard- working, intelligent ones. They make excellent staff officers, ensuring that every detail is properly considered. Third, there are the hard- working, stupid ones. These people are a menace and must be fired at once. They create irrelevant work for everybody. Finally, there are the intelligent, lazy ones. They are suited for the highest office.
Erich von Manstein

A war is not lost until you consider it lost.
Erich von Manstein

Strength of character and inner fortitude, however, are decisive factors. The confidence of the man in the ranks rests upon a man’s strength of character.
Erich von Manstein

Prussian Field Marshals do not mutiny.
Erich von Manstein

If Paulus’s army had capitulated before the end, the Russians would have had the advantage of withdrawing forces against Paulus and against the southern front, where I had only two Romanian armies. Therefore, the resistance of the Sixth German Army, even to the death of the last man, was necessary.
Erich von Manstein
"The Nuremberg Interviews". Book by Leon Goldensohn, 2004.

Hitler overestimated the importance of [technology]. As a result, he would count on a mere handful of assault-gun detachments or the new Tiger tanks to restore situations where only large bodies of troops could have any prospect of success.
Erich von Manstein

The [chief] characteristic of Hitler’s leadership [was] his over-estimation of the power of the will. [To win the war] this will had only to be translated into faith down to the youngest private soldier.
Erich von Manstein