Sodastream soda makerI like carbonated beverages, but it has always seemed to me to be very high priced for what it costs to manufacture.I have a friend that has had one of these for quite a while and decided to try it.Basically the unit uses a cylinder of compressed CO2 gas to carbonate water. You add flavoring afterwards.I saw my friend's unit, which had a manual valve to release the gas, and thought it was pretty much not consistent, and I knew my wife would not like it at all. (She did not like the idea at first but more later).There is a new unit called the Revolution that has an LCD display, and shows the remaining gas, works with both size gas bottles, loads the drink bottles easily and has 4 buttons for 4 selectable levels of carbonation.OK, cool, I'm on my way. What was obvious pretty much right away is that the supplied 1 liter bottles are way too much drink manufactured.I did some research and found that there were 1/2 liter bottles just out, but they did not work on my machine, only some other new one, not electronic.Well, doing a bit more investigation, and seeing that the necks of the bottles were all identical, I tried them and they work. There is an amount of misinformation, mostly from Sodastream themselves about what works with what. There are 2 CO2 bottle sizes, a 60 liter and a 120 liter bottle, and they both fit my machine, and there are many other models the big bottle fits. You save money using the bigger bottle, so investigate carefully if you buy a carbonator and it says the large bottle does not fit.Oh, after seeing how much money is saved, my wife likes it, and she drinks carbonated water alone, "fizzy water". Success!Tips:use large gas bottle, and get the refills, and if the store does not have them, inquire.try different flavors, some suck, some are good (more later)make sure the gas bottle is screwed in snugly but NEVER really tight so that it is difficult to remove, overtightening causes failures.Be gentle loading and unloading the soda bottleUse 1/2 liter containersFlavors:I've tried a lot and have the overall guidelines:The "natural" flavors are in bigger bottles, cost more and taste better.The "knockoff" flavors for Coke, etc. suck.The flavors that use name brand ingredients, like "Ocean Spray Cranberry" taste better.The low sugar flavors are newest and taste good, better for you than the "diet" ones.Stuff I like:Ocean Spray Cranberry-Rasberry, very tasty, both the regular one and the diet onefresh lemon - sodastream naturalsapple peach - sodastream naturals Stuff that is okdiet ginger aleStuff that is disgustingv8 splash (actually any of the splashes seem weak and tasteless)the coke knockoffthe Dr. Pepper knockoffmost of the energy drinks You save money us