The latest Sodastream model has some bells and whistles that'll hit the sweet spot for many consumers. The Fizz boasts the revolutionary "FizzChip" which tells you when you're running low on gas and lets you set your perfect customized gas level. If you like to set it and forget it, and don't want to be surprised when you run outta gas, this model is for you. The older models, still well worth the money, only provide for manual adjustment of the gas-i-ness, which takes a little practice. Watch and learn - the gas is gonna getcha!