So good!
Took Avery's advice and substituted 15 ml of the vodka with genever.

Added 1 ml Malört to boost the bitterness and grapefruity-ness

Didn't read through the recipe before making it, so the mezcal got mixed in instead of being a float. Oops!
Tasted great regardless :)

It’s good this. Didn’t have any grapefruit so used a spot of grapefruit syrup and it’s sweet and smokey and fruity.

This was excellent but seemed a bit watery. Will try again, pre-chilling all ingredients before combining and then adding ice.

Used oude genever in place of vodka to add /some/ flavour. A very very tasty tonic drink.

Used Campari and only had Del Miguey Minero mezcal which has less smoke than Vida. Delicious drink, tonic and grapefruit really make this drink shine.