After trying the pixel 3 for a week and the pixel 3 XL the week. Here are some of my thoughts
Pixel 3 XL
Pros : screen size and resolution / battery life ( getting approximately 5-6 SOT, usage include surfing the web, 1 hour of Spotify , location service turned on, ambient display on, background services running)
Cons: definitely the speaker, I did not realised how bad it was until I tried the pixel 3 so unless u put them side by side, u do grow accustomed to it.
Pixel 3
Pros: form factor , better speakers
Cons: poor battery life ( with the same usage, i am getting around 3-3.5hrs SOT) but the fast charger really helps , gotta play the lottery game of getting a good unit ( went through 4th set).
Overall, if form factor is really a huge issue for you, just go ahead with the XL version because you are better off spending your time doing other things than playing the lottery game which is both time consuming and energy/mentally sapping lol