So I found as you progress your Unarmed skill up the skill tree you unlock new attacks in VATS, leaving you with three options: Normal Attack, uppercut, and crosses. So my question, for anyone in the know, is what are the differences between the three? I see no major difference in damage, or in AP cost, and the game Manuel tied to Steam has been inaccessible since launch, so if anyone wants to chime in with an answer it would be much obliged. Thank you.

From the guide:

All Unarmed attacks inflict the same amount of damage, but are useful if a foe is constantly blocking one of these attacks.

Thanks for the clarification.