Well, it's exactly like the weapons perks... so, what's the difference here?
Like the weapons perks you could decide NOT to buy Pack Mule and still be able to find the Pockets schematics in the world.
The reason I don't like Pack Mule to give you extra slots on its own is because:
- It's "too gamey" or unrealistic (I know, realism!
) because it just magically gives you those extra slots!
- Because I've read lots of people, me included, just prefer to add Pockets over time and completely ignore the (current) PM skill and save the points.
If you, however, tie the perk to the pocket mods, putting even just one point in PM would be worth it and make this perk "palatable" again.
Food for thought IMO...