It’s because you were not taking advantage of the movement component before. It does a lot of interpolation since it’s designed to move a biped in a somewhat natural fashion. Now you have access to all this:
Start by cranking up acceleration. There’s more stuff you can fiddle with.
Technically speaking, I’d use a Pawn + Floating Pawn Movement for this rather than a character; but you may find a way to utilise some of the features that Character Movement component comes with.