Excellent, excellent choice. Absolutely my preferred Gin.
I keep mine in the freezer, and always mix a G&T using the small mixer bottles of Schweppes tonic water. The large bottles tend to go flat too quickly once opened.
I tend to mix mine "long", in a large (chilled) glass. I inherited a 65cc measuring cup from my Father, who spent a lifetime in search of the perfect G&T as a yacht skipper travelling the world. I measure 65cc of Bombay Sapphire to one 8oz (240ml) bottle of Schweppes Tonic Water - that seems to give me the ratio I prefer.
When drinking Bombay Sapphire, or another gin with a large number of botanicals, I find adding lemon or lime is redundant.
We Brits seem to have always favored the G&T to the Martini, it has a lot to do with the circumstances in which the drink is consumed. The Martini to me has always seemed a sophisticated urban drink, ideal for piano bars, whereas the G&T is better suited to outdoor sipping, watching as the sun sets over The Empire
Kevin