I bought two 1/2 liter bottles on sale. They had an expiration date of about 6 months. They also had a water fill line but no line for flavoring. It took me a while to find how much to add. I basically use them just to chill water to refill the liter size bottle. Not worth the money even on sale.
It's so great to have extra bottles so that we can just grab one when we need and don't have to keep refilling. I LOVE LOVE LOVE my Sodastream! It gives me so much joy and keeps me drinking plenty of water!
I order 2 more bottles, I had 1 from when I ordered the the machine. I like to have the drink. mix done up in the bottle, in the fridge cold and ready to pour in my cup. I have 4 of these bottles plus 2 smaller ones I make up all 6 bottles so they are ready to drink. They last me 5 days before I have to make the bottles up again. I like the ease of mixing my own. I'll be honest, I drank a bottle of regular Pepsi tonight because I didn't have any mixed in the fridge. I think Soda stream tastes better than regular Pepsi. I like the fact that a serving is only 45 calories per 12 oz (3. 75) verses 210 calories for 16 oz (13. 125). Besides soda stream mix doesn't have high fructose corn syrup in it. I try to stay away from it because of what it can do to a person's body.
The bottles are narrow and tall, making them generally unstable. Ever time I open the fridge door they fall over. The bottles also only have one fill line for the syrups, instead of the old measuring cups which had multiple options for if you wanted a less sweet soda for instance. The quality seems to be alright, but I much preferred the old style bottles.
High center of gravity makes these fall over WAY too often. Older bottles were WAY better. Been using this system for many years now. The glass carafe wasn't made to fit the carbonation machine so you are just selling a glass bottle which should have been mentioned. If I want to use it I have to transfer the carbonated product to it which seems kind of stupid and the opening is small so there is always spillage. . . unless you want to sell a soda stream funnel. Very disappointed