I purchased this SodaStream used, so it did not come with any of the flavors. All that came in the box was the water bottle and the SodaStream, so that is all that I will review.Pros:1. Easy to use. Since it was used, it didn't include any direction booklet, but the directions were written on top of the machine, and I had no difficulty getting it to work.2. Air tight! During carbonation I couldn't hear or see any signs of leaking between the bottle and the machine. I didn't see any water leaking or hear any hissing, so it looks like all the CO2 is going directly in the bottle. The next step would be a soap bubble test to verify this.3. You control the amount of carbonation based on how long you push down on the machine. If you let go at the first LED, it's low carbonation, 2nd LED gives you medium carbonation, and the 3rd LED gives you high carbonation. I tried at all 3 LEDs and got the expected level of carbonation all 3 times.CONs1. New ones are expensive and you can read up on the cost/benefit analysis in some of the other reviews. If you want to make soda cheaper, then you may not want to invest in this product. If you want to have carbonated water available at your convenience, then this is perfect. I fall in the latter category, so it's worth it for me. I like to make my own fruity flavorings :).To mitigate some of the cost of the proprietary CO2 canisters, I took advantage of my homebrewing equipment. Standard kegging equipment includes a 5lb CO2 canister, which is A LOT bigger than the tiny proprietary canisters that SodaStream wants you to buy. I can't quanitfy how much larger because my CO2 is measured in weight, and SodaStream measures in volume. Anyway, these are expensive up front (around $80), but refills are about $15-20 at the local welding shop (yes, this is food safe. It's meant for beer kegs). Then, I went on eBay and found someone selling a hose with the right connectors on it (this was about $60). This set up also worked like a champ! Pictures are attached. You could probably put the hose and connectors together for a cheaper price (the proprietary side is about $20-50 depending on where you buy), but I wanted to go with something I knew would work.Buying a used Soda Stream and the connectors put me out about $100. It'll take me about a year to get my money back, but considering how frequently I use it, and the convenience, I'm extremely happy with my purchase.