Specifications show that cartridge camping stoves are lighter. For example, the MSR Dragonfly stove (liquid fuel camping stove) weighs at 14 oz (395g) while the MSR PocketRocket stove (cartridge camping stove) weighs at a mere 3 oz (86g).
How much gas is enough? Backpacker estimates that 8.75 oz of gas per day on a mild day is enough for the average user. Double the number when you need to melt snow for drinking water.
For long and/or cold trips we recommend that you use and liquid fuel camping stove.