Well, well, well...what a delightful drink.
I upped the creme de menthe to 1/6 of a shot (new in our collection and the reason for choosing this drink). I could just about discern it...but only because I knew it was there! Need to remember to turn down the sugar syrup if I up the CdM!!

This is a winner! Appearance is opaque white (from the shaking). Slight nose of tequila and mezcal as you start to sip. Terrific blend of tequila and mezcal - citrus and lightly smoke/earthiness is great. Lemon adds to the brighness. This is not a sweet cocktail (I think the lemon helps offset and dilute the relatively small amounts of syrup(s) used). And it isn't a hot/boozy drink either - very nice, and similar to a margarita. I don't get any clear expression of the creme de menthe, but I think that is intentional, as a minty taste would really detract from the tequila/mezcal harmony (maybe helping out with the brightness). Outstanding cocktail!