Made this with Campari, strongest flavor and least sweet of the orangey aperitifs. And I had no Grand Marnier, so I used Bols Triple Sec. I let in a bit of the lemon pulp, and, serving this in a steep martini glass, I achieved a snowy accent on the bottom, resting beneath gorgeous red blush of the cocktail. Very alcoholic, but the Galliano fully mitigates any acidity of the other ingredients, so the result is a powerfully orange flavored, very smooth and not-at-all cloying drink. Superb.
I find Campari atomically bitter, so I almost always substitute it with Aperol. Try that, and increase the Grand Marnier a little bit. For me, the result is delightful.