It won't be any better than any of the previous regular-sized kindles, and the experience sucks on them.
PDFs have a fixed-size baked in, typically 8.5 x 11 or larger, and the Kindle screen is much smaller than that. There's no intelligible way to reflow a PDF, especially not one full of tables and figures like journals and textbooks are. It comes out either unreadably small or with unreadably broken formatting.
So basically it's worthless for that use-case. You want a Kindle DX or a 10 inch or larger tablet to fit PDF content comfortably.
I wish there was an updated DX available. I like my old one. Papers are perfectly readable at this size, it is possible to zoom in to see details in graphs, and carrying around the equivalent of 100 lbs of reference books (that are searchable!) is amazing.
The only drawback is the slow page turn. I usually end up placing a bookmark on any page I think I might want to flip back to as I'm reading. It's annoying.
PDFs have a fixed-size baked in, typically 8.5 x 11 or larger, and the Kindle screen is much smaller than that. There's no intelligible way to reflow a PDF, especially not one full of tables and figures like journals and textbooks are. It comes out either unreadably small or with unreadably broken formatting.
So basically it's worthless for that use-case. You want a Kindle DX or a 10 inch or larger tablet to fit PDF content comfortably.