Each Demon and God, as it should be expected has a personal and unique way of reaching out, and this is even in the kind of energy and manifestation that is and manifests on you.
Aside from the difference that is of a personal and unique nature, which leads you to understand more about certain parts of life and reality, over which they preside and are, the differences can come on your end, such as your openess , timing and so on.
If a lower-ranking Demon would manifest fully to you it would be a very unbearable shock to your system and psyche, in terms of energy, light, voltage, this being of a raw look upon what a summoning and contact would mean. This won't happen as the Gods take care of us, and they reach by ways and degrees we can handle and comprehend.
As with everything, initiating a relationship, with respect and growth of this relation, in time, this will make it so that you grow closer and closer to said God. Of course this implies differences in effects when summoning if you compare with other Gods or Demons that you might never have counsciously tried to meet.
The difference stands in the respective God themselves, as they are uniques and mystically personal in their being. The word personal must be understood also with an added "embodied into existence", as the Gods are the supreme personal as they are beings that are fully living and fully existing.