For nonfiction, research activities, if given the choice, hands down I'll choose an online search for information, as opposed to searching through books. Is that an exclusive choice? Do I always recommend that to students? No, and no. But as a preference, an online search for information just makes sense, for a number of reasons.
However, when it comes to fiction, students are "voting with their feet". Our students have had a number of projects this year in which fiction has been offered in digital format, and overwhelmingly, the library copies fly off the shelves within a week or so of everyone having access to the e-version.