Tried it the original way first, and I'm not sure if it's just my orgeat but I didn't really like the flavor/sweetness of the drink.
Made another with some different specs: 45ml whiskey, 22.5 ml espresso, 15 ml coffee liquor, 15ml demerara simple, 7.5 ml maple syrup. Enjoyed that one much more.
Had this for the first time today, and it was quite nice, although curiously mine didn't look anything like the picture. It was much lighter, almost like a dark orange juice in color.
Little too dry/tart for my taste, so I added about 1/3 oz of honey syrup which worked out pretty well. I'd say agave syrup would be fine too, I just happened to grab the honey first.
Made another with some different specs: 45ml whiskey, 22.5 ml espresso, 15 ml coffee liquor, 15ml demerara simple, 7.5 ml maple syrup. Enjoyed that one much more.