As usual each side has their wins and losses, but overall it's really very close, and it also shows how really niche specialized the 3950X is and that software still hasn't caught up to high core counts.
Currently the 10900K is $660 on Amazon (Amazon's price), the 3900X is $418, and 3950X is $710.
https://www.phoronix.com/scan.php?page=article&item=3900x-3950x-10900k&num=1