...A sawyer filter is small, easy to use and cheap -- around $25
Amen. That is what I use.
The original post was more a general question. Ready.gov's page is geared more for staying at home, but covers both bugging in and bugging out preparation.
I have never used a Berkey filter. Though for home water purification, I plan to rely on inline filters in multiple Reliance Aqua-Tainers I have. That and I keep fresh bleach on hand and drink mixes to offset the flavor.