Let us make this straight and clear.
There is no such a thing as a creamy carbonara. If it is creamy, it is not carbonara.
Another aberration is the addition of onion to the recipe of carbonara.
A proper carbonara sauce should only include the following: egg, guanciale and pecorino cheese. Some pepper, if you so desire, but certainly not onion or - God forbid - cream.
Only an assassin or a mentally disturbed person can add cream or onion to carbonara.