I always have some to hand but I must say, I've not ever used it in my curries. I use it mainly to season my steaks for the barbeque along with a splash of Worcestershire. I also add a little sprinkle to my roast meat and foul and even at times, to the roast vegies.
The Masterfoods brand out here also supplies a "Spicy" variety which clearly has a little more chilli and possibly other heat producing spices.