Squeezing the sides of the Pixel 2XL brings up Google Assistant, not the camera. This is the default behavior. So most users like myself would never experience this "laggy behavior." Also fast-charging works like a champ, as it did before Android Pie update. Can't speak about the older Pixel devices, but they can always roll-back the Pie install if they are that unhappy.
I had the opposite experience. This Android Pie update on my Pixel 2 XL is extremely FAST! This is what the phone should have been in the first place. I saw many problems with this phone since I got it. But this release is amazing.