The main diffrence is the half life as needto said NPP will stay in your system about a day where as deca is about 6 days. NPP also doesn't cause the kind of water retention the regular deca does.
They have the same Androgenic/Aabolic ratio: 37:125. Primo's Androgenic/Aabolic ratio: 44-57/88 which means it is more adrogenic then NPP/DECA which means there is a high chance of side effects. Also I believe the NPP/DECA generally cause less sides in women because it binds to progesterone receptors vs primo which binds to the androgen receptors.