Both are acceptable and, at least to me, they are interchangeable.
One has to be careful with the structure, though.
I love you all - I love all of you.
Both are widely used, don´t sweat it!
And to avoid misunderstandings sometimes one is preferable over the other.
"I wish you all the best" doesn´t means the same as "I wish the best to all of you".
In fact the former means I wish you "all the best", it´s a fixed expression. Perhaps in spoken English it can inflected as if there was a comma in-bettween. In writting, you have to be careful!