Ars did a pretty good review:
Capcom breathes new life into its classic fighting game franchise.
arstechnica.com
Not that I would know anything about Street Fighter II and chunking an untold number of quarters into a machine down at Shakey's Pizza...I mean, that was over 30 years ago...no way could I possibly be that old....
Okay so Street Fighter 2 was kinda a mess. Some moves you just could not counter at all, such as throws. Grabbing and throwing was consider a forbidden art in arcades and fights would break out over it, so shortly after Capcom introduced Street Fighter 2 Turbo that fixed a lot of the issues, including adding staples of fighting games today like throw teching.
SF6 is basically reinventing what it means to be a fighting game, taking everything the genre has learned up to this point and refining it and adding new stuff. For example the new Modern Control style that does away with traditional motion inputs and simplifies all moves, however for some characters it may be disadvantageous such as for Ryu he loses some of his kicks in Modern Controls. Choosing your control style adds another tool for players to express themselves.
Another big addition is the ingame commentator, featuring commentary from actual commentators in the FGC. Your multiplayer matches commentated with proper commentary that can help you learn to be a better player
But a big thing that will help you learn be a better player is the new World Tour mode. On top of an already amazing fighting game, Capcom decided to add an entire single player open world RPG! The whole plot is you're making a character who has only one goal: to become the next world champion. You will travel the globe through different cities, meeting the "legendary fighters" which are the members of the actual roster such as Ryu, Luke, Chun Li, Blanka, and more, and training under them, learning their moves and fighting style, all the while fighting anyone (and anything) in the streets to become the best.
This game is gonna start a new golden age for the FGC.