What Jack said, plus on this you can do something that's physically impossible on a stick: input opposing directions at the same time. This can be very useful with charge characters or when you start using input shortcuts.
It'll be months before I can see any of the advantages that come from using this, though. I need to rebuild my entire muscle memory first. I can barely land my bread and butter combos right now or like... jump on reaction lol. I'm shocked that I was actually able to win online matches day one, though. Casual matches against lower ranked players but still!
I think some of them may have been super confused, though. I must've seemed shockingly bad for a diamond player.