A couple of years ago, I booked a Hawaiian Airlines Vacation package in F. 2 days before the departure I got phone call from Hawaiian advising me that the F was overbooked and was I willing to downgrade to Y for the trip to the islands and keep my F return. In return they offered 2 F R/T vouchers anywhere in their system. After 10 seconds of thinking about it, took them up on their offer. It was Valentines weekend and they treated us like gold. Free drinks, no charges for bags, 2 seats in the bulkhead row. We then booked F to SYD for free a year later using the vouchers.