There are far better alternatives for reducing HCO3 than a filter like that. Either acid addition or boiling are much better options.
Alternatives, surely, but "far better" seems to be a matter of personal preference. A lot of homebrewers might find passing water over a filter readily available at the supermarket to be preferable to boiling or sourcing, storing and measuring acid.
The Brita's reduction of 120 ppm HCO3 to 16 ppm seems pretty effective.