I've been reading the Shaaras' books, Gods and Generals
So what happened when he got to Gettysburg? Up till then Lee had been faced with opponents who willingly ceded him the high ground and then sent blue-clad soldiers up those hills to try to overpower him. The result was predictable, and by the time they reached Gettysburg Lee's army was undefeated. And then the tables were turned. At Gettysburg Lee was faced with a Union army firmly entrenched on the higher ground and yet he sent gray-clad soldiers up that hill to try to overpower them. And just as in previous battles, the result was predictable: the Confederate troops were slaughtered.
So the competent Lee finally met some opponents who were also competent--not Meade, the officers under him who insisted on holding onto their strong positions--and he made the same mistake made by his previous, incompetent opponents. This is the action of a great general?
Why in the world would he do this? Longstreet, his trusted second-in-command, realized the folly and pleaded with Lee to take a different course. Did Lee, at this point, make the mistake of believing his own PR? "My boys are unbeatable and they'll find a way to win this battle, too"? I don't know and I don't know if anyone does, but I doubt if I will ever again think of Robert Lee as a great general, or at least as one of the greatest of American generals. Clearly he was one of the most beloved of all American generals. And clearly there are factors other than battlefield decisions that make for a great leader. Lee had those attributes.
So, in summation, I would have to say, from my admittedly limited perspective, that General Robert E. Lee was clearly one of America's greatest leaders, but only a good general--not great. Flail me if you will, or, better yet, convince me otherwise. I'm just calling it the way I see it.