For knifes the major damage output comes from critical hits. Now with reduced dexterity AP bonus and no Taste for Blood AP, most knife attacks you will ever make within 50 AP is 8:
12 base AP - 36% (@17 DEX)= 7,68 -> 7 AP - 1 from tabi boots = 6 AP per attack. Jackknife can still get to 4 AP but that knife sucks for combat.
Unless Styg changes the balance again it will be much tougher with knifes as compared to sledgehammers. They got hit very hard by the patch. Unarmed got a big nerf too but it still can reach 4 AP, especially with no gloves. Sledgehammers on the other hand almost remain the same. They never had DEX bonus but -2 AP TfB reduction is gone so in the worst case withing 50 AP you can always hit 3 times either with 1 x pommel and 2 regular hits from a steel type hammer or 3 x regular hits from a tichrome one.
Where can i get new patch?
If you play via Steam than the patch will automatically get applied before you start the game.