A fast Kindle?
I don't want to exaggerate how fast the new Kindle is, because it's still not like an E-Ink display can really compete with an LCD or OLED panel in terms of smooth animations or user interface responsiveness. But even compared to the 2021 Paperwhite, tapping buttons, opening menus, opening books, and turning pages feels significantly snappier – not quite instantaneous, but without the inexplicable pauses and hesitations that longtime Kindle owners are used to will be. For those typing notes in their books, even the onscreen keyboard feels fluid and responsive.
Compared to the 2018 Paperwhite (again the first waterproof model and the last with a 6-inch screen and micro USB port), the difference is night and day. While it still basically feels great to read books, I find that the older Kindle can sometimes pause for so long when opening menus or switching between things that I wonder if it still works or if it's completely locked up and is frozen.
“Kindle benchmarks” aren't really a thing, but I tried to quantify the performance improvements by running some old browser benchmarks using the Kindle's limited built-in web browser and Google's age-old Octane 2.0 test. The 2018, 2021 and 2024 Kindles are. they're all running the same software update here (5.17.0), so this should be a pretty good apples-to-apples comparison of the single-core processor's speed.
The 2021 Kindle was about 30 percent faster than the 2018 Kindle. The new Paperwhite is almost twice as fast as the 2021 Paperwhite, and more than twice as fast as the 2018 Paperwhite. That alone is enough to give you the tangible explain the difference in responsiveness between the devices.
As for the new Paperwhite's other improvements, when compared side-by-side, the new screen is significantly larger, more noticeable than the 0.2-inch size difference would suggest. And it doesn't make the Paperwhite much bigger, though is a little bit bigger in a way that destroys compatibility with existing cases. But you won't really appreciate the upgrade until you're coming from one of the older 6-inch Kindles.