Neither are great, but I don't like having to really on RNG.
ah I see you are a man of culture
Ghost Face is better than Pig imo, because he doesn't rely on RNG for half of his power to do anything, in terms of stealth he is much better, because he doesn't take eternity to get from point A to point B. Pig does have her Ambush attack, which can be useful on small loops, but Ghost Face has the potential to cut a chase in half by Marking a Survivor and insta downing them. In terms of Add-ons neither are great, but I think Pig wins this one, because she doesn't have to rely on recovery add-ons to even use her power 6 times per match.
EDIT: +1 bonus point for Pig, she doesn't really have to use slowdown Perks, since part of her power is a slowdown itself if the RNG blesses you.
I like Ghostface more and moving without terror radius and not needing to be crouched is great.
This ain't even a competition, it's a flat out murder.
Ghostface wipes the floor with Pig any day of the week.