Replaced the first one because I bricked it doing a manual update (using USB 3.0, which is a no-no) and I didn't know how to fix it (I do now).
Asked to have the second one replaced when the FPS stopped working. The four replacements didn't work either, and they couldn't replace my finger, so I kept the one I had. (That's the "dry, shriveled skin in the winter" problem.) Just before I got the 4th one, the original one (which is a replacement, but new, not refurb) started working again, so 4 phones, talking to customer support, tech support, then finally development (in California) and the result was no replacement needed.
Started running the Q beta, manually installed. By the second bets, there were too many apps that I depend on that wouldn't work, so I flashed the then-current Pie ROM - and the phone bricked. It turned on in the bootloader (which has been unlocked since day one, since I run TWRP and Magisk), would power off if no power was applied and would show me the barcodes. Any other choice stayed in the bootloader. And there was no USB connection! The PC didn't see the phone. So call for another replacement. It didn't work, so they sent another one - and while waiting for it to arrive, I learned how to unbrick a Pixel 2 - just hold the power button in until the phone vibrates - about 30 seconds. Booted boot.img and the phone was all there, TWRP included. Booted to the bootloader, flashed boot.img, flashed Magisk, (and a few modules that I use), and the phone is now up to the June Pie update. Waiting for the July update in a little over a week.
So, bottom line, I'm on my second one, but I returned 7 of them, a few through a shipping store, a few I just refused delivery (by Google's direction). Not bad, considering that I could have (now that I know how) fixed the first one and not have replaced any.