You will find page after page of You-tube reviews of the Berkley. It is almost a generic presence anywhere that the water quality is suspect world wide, even in the civilized parts of the world.
LAC the Berkkey is not something that just popped onto the scene a few weeks back. It traces its existence back to 1827 when it was filtering 99.999% of the baddies from Queen Victoria's drinking glass.
https://www.consciouswater.ca/gravity-water-filter/
The present systems are just the latest in a 200 year progression.
They have been used in missionary stations, hospitals and homes all over the world where water quality is impossible to imagine.
Many of us preppers in the U.S. keep one of the Berkley filter elements on hand for cobbling together an improvised filter system that we know will hit that 99.999% safety mark ad last for 12,000 liters.
As for the warrenty??? Buy it if you wish. All it can possibly cover is a leak in the tank or spout since there is nothing to break down in a gravity filtration system. You pour into the top and take out of the bottom.