I think this is rather too sweet for an aperitivo. To me it's better like an elegant nightcap. It would be interesting to tweak the recipe a bit to increase the bitterness and reduce the sweetness. Maybe 5:2:2 could work?

The wife and I, along with our Japanese friends, fell in love with this cocktail when we discovered Iwai "45" whisky from the Mars distillery. 80% corn, 20% malted barley, often compared to bourbon but I say that is ridiculous: if it can be compared to anything it would have to be a Canadian. The reason it works is its refined elegance, which allows it to harmonize with the other ingredients. This drink is a classy lady of great charm.

Surprisingly sweet, with the amaro giving a chocolate note and bitterness lingering at the back. Might try with an extra dash of orange bitters to see how that effects the balance.