You hit on every nagging piece I was having!
They do sell a line of flavorings that has "pure cane sugar" on top of the non-diet flavors, but those are about half again the price of the others. Don't know how new that is, but I am happy to see it becoming more common lately. Coke with sugar tastes like heaven compared to the Coke we buy here. Will look closer as to the other ingredients.
Water wouldn't be a problem here as I put all drinking water and ice through a Big Berkey to get all of the nasties out, but as one that can tell the difference between Coke and Pepsi (and will order Iced Tea in lieu of one of them), I do wonder about the flavors.
My biggest niggly was the cylinder. I was trying to figure out why they would sell them in various combinations of Spare and Exchange, and I don't get it. Wouldn't extras ALL be 'Spares' that you 'Exchange' after you use them? That is the one price point I have not factored into this. The cylinders apparently work for ~65 litres, so 1 cylinder per 10 bottles of flavoring - but what $ amount to use?
I greatly appreciate the link - I will check that out and have a feeling that if they went to the trouble to register a domain name, these questions and more I didn't think to ask will be addressed. That is awesome!
What syrups are you using with club soda and where are you finding them?
I have a few bottles of DaVinci here, but not flavors I would use as soda (Gingerbread, Peppermint Patty). I'll check the Netrition site that sells the sugar free ones and see what else they might have.
Thank you SO much for taking the time to respond so thoroughly to this. This is exactly the kind of information I was looking for. Still leaning in the buy column, but now I feel like I have the questions I need to go find answers for, and the cylinder issue just may be the kill switch on this whole thing.
Merry Happy to you!
PS - Where I'm from, matters not if you are drinking a Diet Dr Pepper or a 7up - its all "Coke" to us! I am trying to use "Soda" more often, but you know the old expression: You can take a girl out of the South, but you can't take the South out of the girl. 
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