This review has some decent comparisons:
https://youtu.be/KRHmi9bnuK0?si=cYo9MHdMjVm51KOO
I suspect it will mostly be an upgrade from the Oasis I bought 8 years ago, sans the thin aluminum body and physical buttons. The contrast is likely better; I've always found the text on my Oasis slightly grey. And with regards to the background, unless I'm outside, I always use the backlight.
So the only thing that may be slightly worse is the clarity of the text. There's no question on my Oasis it's very sharp, so it remains to be seen if I'll care about that difference.