i haqd carried one for a while, but the G.I. canteen cup is a whole lot bigger and better for my uses. it can boil water, is shaped better to carry, will hold your survival kit inside it. you can cook in it better. so i have not bothered with the small or large sierra cup for a while. i also like some of those surplus german/swedish mess kits for a survival kit carrier. they are fairly compact, have a lid and will hold your whole survival kit as well as work as a cooking/water purifying container. i think i bought them from cheaper than dirt or sportsmans guide. also bought a couple of the gi type cups from sportsmans guide , they work pretty well for my needs.
alex