Frankly, we just bought business class on DAD-HAN. We did get lounge access. Fare was refundable, we didn't have to worry about luggage limits or long check-in/security lines and the price was very very reasonable (IIRC ~$120). And I think there were only 3 or 4 pax in the 16-seat cabin.
Oh, and we booked ~3 months in advance and the schedule only changed once. (About a week prior to departure, flight moved 45 minutes later).