I actually downsized and went to the regular pixel from the s7 edge and so happy I did it. I'm getting better battery life of the pixel than I did on the s7 edge so I presume that would be the same for the XL giving it's quad HD display over the 1080p regular pixel.
I had the XL and returned it for the regular size, just because I didn't want a big phone anymore and realized that the battery life was still amazing on the pixel. The display is awesome, and it's even better on the XL. May not be as good as the s7 edge side by side but you can't tell a difference just looking at the XL, it's beautiful! The software experience is insane, the smoothness and speed is quite impressive. Now we can talk like iOS fanboys and say "it just works" because it really does. I don't manage my battery, ever even have to figure out what's "eating away" at my battery like I constantly did on my edge. I miss Samsung pay, but to me I don't miss it enough to switch back.
I say go for it and get the pixel XL! Google is now extending their return policy if you order it directly from them. So you get more than 14 days, I believe 30 if I am correct to see if you really like the phone.