I thought that was an affecting scene.
It's not in the last act but the only part I really remember disliking was when the Jews give him the cake in front of the Nazis and then he kisses that girl, as if they'd all lost their minds and decided to try as hard as they could to blow their cover.
I didn't read the book but two things I know aren't accurate: the real Amon Goth was a boorish slob, and the list was not made by Stern, it was made by some guy who was selfish and corrupt and took bribes to determine who made it on the list. Neither of those do any internal damage to the movie the way that that crap with the cake does, IMHO. Also, Schindler's wife was important to the operation and doesn't get any credit in the movie.