I watched it as it came out. It wasn’t a lot of new content, but it was nice to see what happened in between the defeat of cozy, tirek and chrysalis to twilights second coronation. I like reliving all those fun times, and watching the ponies recall those moments as well. Gave a nice little send off, some closure I guess. I’ll post any of my ideas with spoilers content under the spoiler, so you don’t have to have anything exposed before you see it.
Spoiler
my one complaint is that I wish luna and celestia recounted when twilight and her friends got the elements of harmony. It was a life altering event for everybody involved, and would probably be very important to them. It was twilight and co using the elements that brought the two back together. At most, all we got was when celestia decreed that twilight should stay in ponyville with her new friends. It’s a bit nit picky, but I wish they covered that.
It was also interesting to see spikes memories, and to see just how much twilight means to him. We always knew that their relationship was close, but it was often told from twilights perspective, and her learning to appreciate spike more. Going from “dragon who sends letters” to the royal friendship ambassador. And we got so few spike episodes, I felt it was easy to forget their relationship moments. So spike recounting all his experiences with twilight was a very nice touch. Twilight grew over the series, but spike grew up as well. And he wouldn’t be the same dragon he is today without twilight being there, and him being there for her.