This is my go-to Dry Martini. I chose a 5:1 ratio as our 'preferred' Dry Martini specification in deference to David Embury who writes of this cocktail...
Have you tried 4.5:1 ? I find it works very well and balanced the ‘wet’ and ‘dry’ qualities very well. Simon’s suggestion of one dash orange bitters also adds an extra dimension. Bitter truth bitters tend to be more nuanced here where there’s so few ingredients to horses amongst.