60l are misleading

what you should consider:
1 in normal bubbled water, obtained max 45l. That still advertised with 60l, is umverschämt (with hardly bubbled water could be safely advertise with 100l, the whole thing but not serious).
2. The carbon dioxide is significantly more volatile than when purchased soda and loses in the refrigerator quickly its liveliness.

The only thing that speaks for the unit, is the elimination of transport costs of conventional Sprudekisten.