Since the “extra” fares rolled out I’ve purchased two of them: the first was an international D1 ticket that had a fair amount of uncertainty, and extra was only $500 more to make things fully refundable. I did that so as to not have a massive e-credit should I need to cancel. The second was also an international fare, though in PS where the extra gave me F on the domestic segments for only about $400 more (I honestly didn’t know that was a new perk of the extra fare for PS, as in the past it was super annoying it only booked into C+). Anyway a small sample size, and only for some personal international leisure travel. Definitely not booking them for my standard domestic tickets whether in F, C+, or Y when I can just take a credit if needed without giving DL a massive loan.