Having the Big Book in my smartphone and Kindle e-reader is really a great convenience. I prefer it over a paper copy in Big Book study meetings, because I can add highlights and notes and easily find them later. Searching the text is also a great advantage. I haven't personally found any textual errors The page numbers are broken, though. In the current (as of Oct. 30, 2019) update of the book, "go to page" searches are useless. For example, go to page 86 takes you to page 165 of the actual book. Previous updates worked correctly, and I'm confident the publisher will correct the problem, but for now it's annoying and renders the e-book less useful.
Latest update broke the page numbers