I applied the patched on both my systems (iMac 2013 core i7 on Sierra under HFS+ that was upgraded to High Sierra for the occasion, and a MacBookPro 2017 already on High Sierra under APFS), and I can confirm that both my systems are seriously and objectively slowed down, 4 days after the patch now.

From what I could observe, applications taking the most serious hit are electron based (like VSCode, that went from smooth as silk to mildly sluggish) and Safari.

Docker on mac has also taken a hit, although I couldn't quantify it objectively.