Yes, I have E-books. Yes, I use E-books. Yes, I write E-books. and so on.
I use them as reference material, I use them as sources for articles, and like that.
Other than my own, I don't think I have ANY fiction in that format.
I've got everything from encyclopedias to the works of Flavius Josephus as an E-book, and more different translations of the Bible than I can name or count, at least two translations of the Holy Quran, and 'the Hammer of the Witches' in electronic, and SEARCHABLE format.