Maybe it is that I just know the Giulini recording better, but I just cannot be friends with this one. Bernstein has created with the London Symphony Orchestra a heavy sound, heavy and slow. Five minutes difference of the whole work might not be very much (the whole work is one and a half hour), but to my ears everything sounds more serious. Now you might expect that in a mass for the dead. But Verdi was also an opera composer. He likes to tell stories. In Bernsteins version, the story loses from the sanctified tone.
This recording is made in the Royal Albert Hall in London. The monumental venue gives it a slightly spacious sound. Maybe it is that sound that makes it difficult for me though, as that much space removes some of the crispiness of the Giulini recording.