I've been using the Pixel 2 for a couple weeks now, enough time to get a feel for battery life. I use AccuBattery Pro to monitor battery life, particularly paying attention to the percentage of screen off time in deep sleep and correspondingly the percentage decrease in battery while the screen is off.
Generally, I am finding battery life on the Pixel 2 to be no better or worse than the Nexus 6P. When all is right I see nearly 75% of screen of time in deep sleep and about 1.5% battery decrease while the screen is off. AccuBattery estimates 5h 18m of screen on time, 36h 22m of screen off time, and 25h 39m of combined use time. All these numbers align to my use case.
I have found that for some reason Google's automatic wallpaper change prevents the phone from going in to deep sleep and therefore battery consumption jumps to around 5% of screen off time. Consequently, I don't let Android automatically change the wallpaper. Clearly there is some bad programming with that feature because I don't understand why such a thing should prevent the phone from going into deep sleep. In fact, I thought Android O came with a feature that better managed such bad behavior by forcing apps to allow deep sleep.