Healing Speed is a three-level Survival upgrade that makes Joel use health kits faster. Healing locks you in an animation, so a quicker one helps most when enemies are close.
Crafting Speed
Cuts the time Joel takes to craft items from his backpack.
Listen Mode Distance
Widens the radius in which Listen Mode reveals enemies through walls.
Maximum Health
Raises Joel's maximum health. Buying a level while hurt also refills his health completely.
Shiv Master
Level 1 lets Joel stab a clicker that grabs him if he has a shiv. Level 2 stops a full-durability shiv from breaking when used this way.