Quick take
Water-to-Go is the stronger travel-first bottle ecosystem. WaterH is compelling when hydration tracking and a reusable smart-bottle experience matter more than maximum travel-purifier positioning.
Travel use
Water-to-Go emphasizes international travel and broad contaminant-reduction positioning in a lightweight filtered bottle.
Filter capacity
Water-to-Go commonly rates its 0.75 L filter around 200 liters. WaterH replacement filters are typically marketed around 40 gallons / 151 liters or roughly two months, depending on use.
Technology and user experience
WaterH leans more toward smart hydration and everyday use, while Water-to-Go is more explicitly built around portable purification.