A whole lot of not recommended reviews coming in, watched 3 already. I believe there would be more, but many reviewers tow the line by not wanting to completely bash Google.
Largely around:
Weak battery results
small 64gb storage and only up to 128gb
using older UFS 2.1 flash storage vs UFS 3.0 which is 2x faster and now used by the Note/One Plus
no 4k60
no wide camera
removal of wide camera on front
face unlock not supported by apps yet, back to passwords
removing free unlimited photo/video storage
radar gesturing is just a sales gimmick, few uses
no increase in charging speeds since Pixel 1 at 18w
using the older 855 chip when other flagships are on 855+
same standard camera lens as Pixel 3, which will receive the Pixel 4 software upgrade diminishing P4 advantages