A few months back I read sacred ties while on my last field exercise in Germany, it was an interesting read about Custer, Rosser, Du Pont, Ramseur and Merritt during their time at West Point and Beyond. It opened me up to these men a little more and I felt like I knew them more personally than I did before. That being said I would say that Custer is somewhere in the middle of Sacred Ties version of him as the "Doting husband and great General" and Nathan Algren in the Last Samurai's "Idiot who fell in love with his own legend".
I believe he as a PRIME example of an officer who was advanced too quickly due to the Army needing trained men like him for command. It could not be helped, but the Little Bighorn (in my mind) ranks up there with Pickett's charge in the "he should have known better" column. Moral of Custer is never leave your Gatlings behind, and always ALWAYS bring your full basic load+25%