An excellent drink "All Jacked Up" is; but sweet, I think not. One person suggested reducing the sweet vermouth. I used Dolin sweet vermouth, and it was just right. Some sweet vermouth are very sweet (e.g., Cinzano). This is a drink where the brand of sweet vermouth will make a distinct difference.
Myself, I would not reduce the sweet vermouth with this drink, primarily because it would throw off the drink's balance. The drink would, I believe, have a smokier flavor, and the Fernet Branca would also, I believe, be more pronounced. As it is, everything is in its place. In short, "If it ain't broke, don't fix it!"
Revisited this drink just now after trying it a few years ago. I agree with others, it's riding right up to the line of being too sweet (using a house vermouth blend of CAF, Cocchi di Torino & Alessio), but the ingredients are so well integrated it didn't bother me. As others said, the cocktail nerd in me perhaps wants something more intensely flavored (I would probably look to add a dash of bitters, say Dale's Pimento, or a rinse/atomizer spray of something, before changing the ratios), but for the average customer, this is a great introduction to some typically intense ingredients.