They also have one of the lowest cost options which uses glass bottles. I've been incredibly happy with the Logan. Even if it's not as pretty as something from aarke.
I'm also happy with my Sodapop Logan. I prefer the sliding/rotating door design over the vertically closing design of Sodastream's models.
Unfortunately, it can't fully empty the CO2 cartridges since the device needs a certain minimum pressure to close some sort of valve. If the pressure is too low, the water doesn't really get carbonated and water splashes everywhere.
I'm having trouble discerning from their website who manufactures their cylinders, but they appear identical to the Sodasense ones used by all the American brands (sodastream/ninja thirsti).
Do you mean the glass bottles or the CO2 cartridges? I think the latter are more or used by all brands of these sparkling water machines in Germany. Seems to be like an industry standard to me.
There are adapters that can be used to refill them with co2 bottles purchased from a local supplier though. IMHO a 1 time purchase from a US company that then liberates you from them via enabling local production of your stuff is acceptable, for some it may not be.
What makes you think that all these CO2 cartridges sold and used in Europe are manufactured by a single company in the US? I couldn't find a source on who actually builds them, but found the confirmation that the fitting is a EU-wide norm across all brands selling these 425g CO2 cartridges. The norm is ISO 10297. I don't see why there would be only one company producing these things. And if so, I'd rather expect it in some low cost country rather then the US?