Ok, I finally saw it. It was pretty amazing, much better then previous specials.
Thanks to this I now appreciate Sunset in a whole new light. She going back being "mean" told us more about her then most post-Rainbow Rocks stuff ever did; being isolated is most probably what caused being worse, which explains why Celestia insisted for Twilight making friends; she feared she would have become like her. Oh, and Celestia reuniting with Sunset was just as heartwarming as I imagined x3.
Speaking of Twilight... DEAR GOD, TWILIGHT! Seeing her being her squeaky geek-self again after such long time was epic. I missed her being like that.
About Wallflower, she's basically like a Fluttershy gone mad with power. I'd like to point out though that she's the most teenage character I saw in EqG, since she suffers in a way typical of a girl her age.
Finally, about the humane 6, I've found the scenes where we see interacting with eachothers pretty good: we don't see them doing anything we don't expect them to do, but is nice seeing them dealing with irl problems using irl world words. Special mention goes to Pinkie; seeing her using some tough girl attitude instead of just her usual baby talking was surprising. Also, never expected to find a drone cute x3. I give it a 4.5\5.