Her speeds are the same.It seems like in DoA6, Kasumi is able to land combos more easily, but I feel like her speed has been reduced a bit. In DoA5 she had a pretty good speed advantage over most people, I used to be able to out-jab most people all the time. However that's no longer the case, people can jab-draw me all the time which is strange. In DoA5 you could pretty much out jab most people.
Her juggles seem to be easier to land than in 5 though. Which is good.