Do you find it a bit pretentious of an artist to use a certain method merely to prove his stamina or loyalty to tradition? (Reminds me of bullies who say I can fight you with one hand behind my back.) I hope that is not why Nick Brandt sticks with film. Although, after reading some posts, he did seem a little defensive of rumors that he composited his animals onto background scenes (for example the leapord in the tree). If he did composite, WHO CARES! One's imagination should rule his artistic vision, not his methods of production.
I have faith that if Nick could get supior results by shooting digital, he would do so. It makes sense he shoots film because of his need for the infrared effect. And because there are (to my knowledge) no infrared converted MFDB, the next best thing is 6x7 infrared roll film. He can't use a 35mm DSLR because his prints are over-sized.
I read that Nick is disappointed that his favorite infrared B&W film, Macophot 820c, has been discontinued. It was the best he said. It seems infrared is a dying art. What a shame.
But yes, like the previous post said, the success of Nick's prints is primarily the subject material and its composition. A feat that can only be accomplished by years of relentless pursuit and patient waiting for that one golden shot. In fact if you ask me, I think the modern path to fame as a fine art photographer is not technical mastery, but rather specializing in one subject area and creating a collection worthy of museum exhibition. Joey L. is another case in point. Joey didn't invent his style, he perfected his subject.