I flew KE 25 last month with the Apex Suites in Prestige Class. 777-300ER, window seat.

Agree with OP on the privacy. I felt like I was completely alone the entire flight and I've never slept more deeply on a plane despite the tiny pillow and stuffy bedding. That said, what always keeps me second-guessing Korean Air is the uncomfortably hot cabin temperature. KE generally keeps things on the warm side. If you ever fly them, pack a pair of shorts and t-shirt or risk a sweaty flight.