The cylinders are rented by the consumer and are
-taken back when a new cylinder is purchased
-refilled
They buy the CO2 from coop or their retailer, but they only have the cylinder on loan. If they lose the cylinder, they have to buy a new one, which they can trade in.
There is certainly more about this on the Soda Stream website.
According to my information, this only applies to local partners and not to online shops like us. You can find the partners under this link.
https://www.sodastream.ch/store-locator/
According to the official product documentation, no:
https://support.sodastream.com/hc/en-gb/articles/360009219593-Which-carbonating-bottles-fit-my-Sparkling-Water-Maker-
It's compatible the the glass caraffes only.
The Sodastream Crystal model is offered once normally, other times with the abbreviation 2.0. Technically, I have not noticed any difference, perhaps this abbreviation was introduced with new machines or simply omitted in some cases.
Yes, the set includes 1x 60 litre C02 cylinder and 3x 615 ml glass carafes. See also product page -> Specifications -> ↓ Show more -> Scope of delivery