Compared to the earlier generations of Kindles, yes, they are considerably faster, but you'll likely never get "instant" page turns on an e-ink display. For what it's worth, I've never found the page turning to interrupt my flow - except when I accidentally drop it on my face and it turns pages! :D
Some e-ink can be refreshed ~10fps I think. And old kindles had the ability to increase turn speed but it could leave artifacts on the screen, iirc