Not much kept me away from the P4XL. I'd love to see a bigger battery (but not betting on it since that's never been a priority for them). If they go with glass backs again, I'd love for the black option to be frosted or matte. I hope to God that they don't use that U-shaped camera module we've seen leaked, as it looks terrible in my opinion. I was ok with the square module on the 4.
Other than that, they can keep the Soli module, I'd be open to it, but perhaps a in-display FPS, too? And at least maintain 90Hz.
We shall see.