I owned a Sodastream, and I can't tell the difference between that model and the Phillips brand of carbonator. They both do the job equally well. I'm thrilled that I saved myself all the money it would have taken to get a Sodastream. I have used the Phillips for two weeks...which means I can't comment on its longevity. It could break right after I write this review. (If it does, I'll update the review.)Both units are very simple. Screw in the CO2 cannister and push the oversized button to carbonate the water. I don't use sweetener. I like plain H2O.If you're new to this product, you might be wondering how long the CO2 cannister lasts (I don’t think the type of carbonation machine you purchase, whether Sodastream or Phillips, makes a difference). After all, you want to save money on eight-packs of Bubly, right? Overall, you will save money. . .except you'll drink more water, which might end up being more expensive. Still, as far as dollars to product, this method is less expensive (once you surpass the initial cost of the machine and cannisters). Again, I save money because I do NOT buy flavors.Based on my body weight, I need to drink about a gallon of water per day. (If you're interested in improving your health, divide your body weight in half and drink that many ounces per day.) That means I need to drink 128 ounces or so. Four Phillips bottles of carbonated water allow me to meet and exceed that goal by about four ounces. Each bottle is one liter. (1 liter = 33.814 ounces).Over these last two weeks, I ended up drinking three or four bottles of soda water per day. I pumped the oversized button three or four times per bottle. The problem is you have to pump more as the CO2 cannister nears empty (at the end, it was five or seven times). On the thirteenth day, I couldn't get any fizz worth enjoying, so I figure I got twelve days of use out of a single cannister. Those last few days produced mediocre carbonation, hardly worth drinking. Once the carbonation is gone, the water tastes unpleasant to me.I just replaced the cannister at Walmart for $18 after tax. That means I spent $1.50 per day on my habit (18 dollars / 12 days = 1.5).Previously, I would purchase Bubly brand eight-packs. That came to about $4.75 after tax, each, or $0.60 per can. I would need to drink 11 cans per day to match four Phillips bottles. That’s about $6.60 per day—as opposed to $1.50 per day making my own fizzy water. I’ve saved roughly five dollars per day.THE HIDDEN CATCH: I didn’t usually drink Bubly every day. Carbonated water was a treat that cost me about $25 per month. But now that I can make my own treat whenever I want, I am looking at about $45 per month refilling those cannisters.THE HIDDEN BENEFIT: I am more likely to meet my healthful water-drinking goal if the water is carbonated. It makes me feel like I’m being naughty, so I drink more.So, look, if you are a soda hound, making your own fizz is the way to go. But do the math, because it may or may not save you money.====Update.For those of you who are like me: canned soda, whether just water or cola, is only good for a few minutes after you pop the top. I rarely finish a Coca-cola unless I drink it right away. It's the same for Sodastream and Phillips. The carbonation is just begging to escape the bottle. Therefore, I marathon drink my fizzy water, because if I wait, the beverage will lose its "oomph" and I'll dump it out, wasting CO2.That might not be you, but do consider that you might be speed-drinking these 1-liter (33 ounce) bottles just to keep up with the C02 loss. It's less to lose if you're drinking a twelve-ounce can of soda. Something to consider.