I don’t know if you’ve used a recent paperwhite but they’ve gotten very responsive.
I have the newest paperwhite (prior to the one announced here) and it is incredibly fast and zippy compared to the kindles of old. And they claim the new one is even 25% faster.
I too have the previous generation Paperwhite and it's a laggy piece of junk. About the only thing it's even remotely zippy at is flicking through pages rapidly when I accidentally brush my wet hand against the stupid touchscreen while I'm in the bath.
I have the newest paperwhite (prior to the one announced here) and it is incredibly fast and zippy compared to the kindles of old. And they claim the new one is even 25% faster.