Before placing an order, you might want to know what it will cost to go this route. Typical prices for concentrate are $8 to $14 per quart, $7 to $10 for pints, and $3 to $4 for 4-ounce bottles. Shipping will be expensive—count on an additional 30% to 70%, depending on how much you order and the distance. Depending on these factors, flavoring costs are likely to range from $ to $ per liter. Obviously, at the high end you won't be saving much if any money over SodaStream's flavors, once you add in the cost of sweetener; but if you can buy a few pints or quarts at a time, the total cost (concentrate plus sweetener) will fall in the $-$ range. Most or all of the ingredients will also travel less than the SodaStream bottles, and what does travel will mass less, which all adds up to being better for the environment.
When carbonating water, we took into account how easily each soda maker allowed us to control the fizz levels with buttons, levers, or presses. We visually observed the overall fizz level and bubble size in the sparkling water from each soda maker. Then we tasted the sparkling water from each machine to compare mouthfeel and flavor (we used filtered water, but CO 2 does add carbonic acid to water, which produces a slight tang). In addition, we noted how much space each soda maker took on the counter, as well as any extra design features.