Gin-Basil-Cucumber & Tonic

I'm not the world's biggest fan of Bombay Sapphire. It's by no means a bad gin, but sometimes I feel like it's a little over complex, other times I find it thin and uninteresting. I've made cocktails and when something just hasn't been quite right, process of elimination has often turned to the inclusion of Bombay. All this being said, there is one cocktail where I feel a London Dry just won't substitute. For the Gin Basil Cucumber and Tonic— and I still don't know why, it has to be Bombay.

The Gin, Basil, Cucumber & Tonic.
1oz Bombay Sapphire Gin
4oz Tonic Water
1/2 teaspoon of sugar
3 leaves basil
3 slices cucumber

Muddle basil and sugar in gin, then add cucumber slices and ice. Top up glass with tonic.