They both "work" in same way,
but for 2 different purposes.
you can:
use GrabPoint to grab/pull atom with physics enabled
use ClothGrabSphere to grab/pull atom with Sim enabled (Clothing or SimSheet atom)
Basically to work...you need to toggle them on/off (or select/deselect).
ClothGrabSphere doesn't work when spawned, you need to toggle
ClothGrabSphere atom off/on (to release/grab sim stuff).
Same with
GrabPoint you have to select atom (with physics enabled) to grab it, than you can drag
GrabPoint to pull atom (in whatever direction).
That's the gist of it...here an example using ClothGrabSphere (to hold SimSheet):