I've already ordered PET film protectors for my pre-ordered Pixel XL.
I hold out hope that I might find glass protectors useful. Of course on my N7, they just didn't work.
But overall, even when then do "work" it's hard for me to get past the visual of having a slab of glass on my phone. Film is not as protective, but it doesn't shout "hey, I have a slab of glass on my beautifully designed phone" from across the room. Film is almost perfectly invisible, if it's cut right and installed properly, so that's why I typically use film.
Just my opinion, and I remain open to using glass, I just want to see one that that is less visually offensive to me.