Personally, I don't feel that the violence was "gratuitous" but important to the storyline. If you do not like violence in film, do not see this movie.

I enjoyed Michael Keaton's performance as Batman, but it was still too close to the camp version of the 1960's.   Christan Bale IS the Batman of contemporary comic books and conveys the conflicts and demons of the character better than any actor to put on a cape and cowl.