There is a difference between chlorine and chlorine dioxide. People who use chlorine bleach are doing so with no real idea of what the appropriate dosage is to actually be effective. Chlorine dioxide in its various forms has a specific dosage depending on clarity of the water and the temperature of the water - there's a chart to help you decide if you really need to wait four hours or half and hour.

If you get sick while backpacking, unless you are out for more than nine days, it's not likely to be giardia, but something else. Were I stuck and filter broken I would simply drink the water available untreated on my hike back to the car - giardia is misery but treatable. In areas where reports of crypto are made, nope, I'd be building fires and boiling it instead. Not really any treatment for such an infection, and it's worse than giardia. Also rarer, thank goodness.

The Lifestraw has a too-short lifespan to be of interest to me. The 200 gallon lifespan of a Hiker Pro makes more economic sense. The backflushable Sawyers with their million gallon guarantee make another kind of sense.

All in all, it's up to the individual, but after talking to too many giardia infected folks who rang up hospital time I filter and don't sweat it.