The Dark Knight is often considered to be one of the greatest superhero films ever made. On aggregating review website Rotten Tomatoes, The Dark Knight has an approval rating of 94%, based on 332 reviews, with an average score of 8.5/10. The site's critical consensus reads, "Dark, complex and unforgettable, The Dark Knight succeeds not just as an entertaining comic book film, but as a richly thrilling crime saga." Metacritic, which assigns a normalized rating based on reviews from top mainstream critics, calculated an average score of 84 out of 100, based on 39 critics, indicating "universal acclaim." CinemaScore polls reported that the average grade cinemagoers gave the film was "A" on an A+ to F scale; audiences skewed slightly male and older.Roger Ebert of the Chicago Sun-Times, awarding four out of four stars, described The Dark Knight as a "haunted film that leaps beyond its origins and becomes an engrossing tragedy." He praised the performances, direction, and writing, saying the film "redefine[s] the possibilities of the comic-book movie." Ebert stated that the "key performance" is by Heath Ledger; he pondered whether he would become the first posthumous Academy Award-winning actor since Peter Finch in 1976. The Oscar was awarded to the late Ledger. Ebert ranked this as one of his twenty favorite films of 2008.Peter Travers of Rolling Stone wrote that the film is deeper than its predecessor, with a "deft" script that refuses to scrutinize the Joker with popular psychology, instead pulling the viewer in with an examination of Bruce Wayne's psyche. Travers praised all the cast, saying each brings his or her "'A' game" to the film. He says Bale is "electrifying", evoking Al Pacino in The Godfather Part II, that Eckhart's portrayal of Harvey Dent is "scarily moving," and that Oldman "is so skilled that he makes virtue exciting as Jim Gordon." Travers says Ledger moves the Joker away from Jack Nicholson's interpretation into darker territory, and expresses his support for any potential campaign to have Ledger nominated for an Academy Award, Travers says that the filmmakers move the film away from comic book cinema and closer to being a genuine work of art, citing Nolan's direction and the "gritty reality" of Wally Pfister's cinematography as helping to create a universe that has something "raw and elemental" at work within it. In particular, he cites Nolan's action choreography in the IMAX-tailored heist sequence as rivaling that of Heat (1995). Manohla Dargis of The New York Times wrote, "Pitched at the divide between art and industry, poetry and entertainment, it goes darker and deeper than any Hollywood movie of its comic-book kind." Entertainment Weekly put it on its end-of-the-decade, "best-of" list, saying, "Every great hero needs a great villain. And in 2008, Christian Bale's Batman found his in Heath Ledger's demented dervish, the Joker." BBC critic Mark Kermode, in a positive review, said that Ledger is "very, very good" but that Oldman's turn is "the best performance in the film, by a mile"; Kermode felt Oldman was deserving of an Oscar nomination.Emanuel Levy wrote Ledger "throws himself completely" into the role, and that the film represents Nolan's "most accomplished and mature" work, and the most technically impressive and resonant of all the Batman films. Levy calls the action sequences some of the most impressive seen in an American film for years, and talks of the Hong Kong-set portion of the film as being particularly visually impressive. Levy and Peter Travers conclude that the film is "haunting and visionary," while Levy goes on to say that The Dark Knight is "nothing short of brilliant." On the other hand, David Denby of The New Yorker said that the story is not coherent enough to properly flesh out the disparities. He said the film's mood is one of "constant climax," and that it feels rushed and far too long. Denby criticized scenes which he argued to be meaningless or are cut short just as they become 

Question: what was davids comment towards bales performance?
Answer: voice that's deeper and hammier than ever

Question: What did the Bale think of Al Pacino's role?
Answer: electrifying