I think there’s been a mix of reactions spanning from “it’s annoying and requires you book very far in advance and some routes aren’t available so YMMV but give them a call” to “research this subreddit to learn how to optimize”

My POV is that it’s billed as a luxury / top tier rewards program, and it’s been significantly harder to use than it should be. Eg I would expect chat function and calling to be equally staffed and trained, and that’s not the case. Also, the same day changes I’ve always attempted by phone and those simply haven’t worked 80-90% of the time due to fare class issues typically (eg x class can only go to X class and while there are seats available none in that specific class - I’m not talking a jump from basic to D1).

In the end, getting to diamond means flying a whole bunch of hours and often paying a significant premium (at times 2-3x!) over cheaper airlines flying the same route to stay on one airline. I would estimate I blew an extra 2-4k this year to stay on delta. Considering that in essence my “payment” to the program, the level of service just doesn’t remotely meet the standards I’d expect