Superb drink, but strongly recommend reducing the sweetness. The bitterness of the Suze really adds depth, but it is knocked out of whack by the Amaretto and the Simple Syrup. I bought a bottle of Suze just for this and I am glad I did!
I made it with 20mL Bianco vermouth and no sugar syrup which worked well served straight up, although I did find the Suze a bit too dominant and I would cut that back next time (though I expect the both the extra bitterness and the extra sweetness are required when served on ice).
Incredible drink. Personally I found the recipe as written slightly lacking in the bite I want from a spirit-forward drink, but upping to 3cl of each spirit solved that. I was initially skeptical about the 2:1 syrup:Amaretto ratio, but the Amaretto shines through more than you'd imagine. Love what the Suze brings without becoming overpowering.
I took down the bourbon by about 5 ml because I found it dominated an otherwise complex cocktail, and substituted my homemade whitebeam liqueur for the amaretto. Absolutely gorgeous. P.S. To the previous commenter, cocktails don't have genders.