This semester, I've been teaching all high-level students. Like high enough level that I generally just talk at a pretty normal pace, but I use somewhat simplified grammar and vocab and my students seem to always be on the same page. When writing, I don't filter my words at all and just use my normal style. Many of them have lived overseas, or are preparing for internships in the USA.
And, it seems that almost without exception, they want to use inauthentic material, that is stuff from ESL textbooks. It's like a kind of crutch I guess and what they've been using for years and what they feel comfortable with. Except when students are at such a high-level, they actually need authentic material. Here's why I think so:
1. Students need to be challenged. Even the highest-level ESL textbooks are actually too easy for most of these students. And at what point do these extremely high level textbooks become somewhat ridiculous because the students should actually have moved to authentic stuff.
2. Students need confidence. They need to be shown that they actually can read (and understand) an article from the BBC or Newsweek. They probably won't read these things on their own, unless you show them that they can actually do it.
3. Students need strategies for when they don't understand everything. If a student can breeze through a reading in less than a minute, or listen to something once and understand everything, it's not really helpful. Students need to struggle a little bit, even high-level ones. They need to adapt and use learning strategies.
4. Even the best designed textbooks are "artificial." The grammar and vocab always has an element of not so much like real-life. Authentic materials are real-life.
5. Authentic materials create in interest in the class. Which textbook has an article about the Sewol Ferry Disaster? None of them. What about Park Geun Hye's recent visit with Angela Merkle? None of them. Except these are the topics in the news these days and what students actually want to talk about. It's actually really helpful to take what the students are talking about in Korean and do it in English, because they actually have a lot of insight and background knowledge about the topics.
IF you must use a textbook, here is one of the better ones: