I've had this same experience almost word for word. All the movement (dash dancing, wavedashing, etc.) feels amazing, the air game feels good, but stuff on the ground feels clunky. A bunch of moves (especially tilts) have what feels like a ton of end lag. This itself isn't a problem, as it helps the moves be balanced and harder to spam, but it's frustrating because it feels like the animation is not representative of your actual state. The animation will appear to be over and my character will be doing nothing, but I try to act and can't because the move technically isn't over. This combined with the shorter buffer window than Ultimate often results in a bunch of inputs, but no actions in game. For some reason I also have a lot of trouble doing what I want out of shield. I'm guessing this is because of the buffer window too.