ramdom thoughts:

while it might be perfect for emergency back-up and storage in mini survival kits simply by virtue of being small/light and being used instantly, if its like other "straw" filters:

-they're only used for direct-drinking
-cannot be used for cleaning cooking water or washing water
-clog easily
-cannot be cleaned
-do not kill viruses (not much of a problem in US/Canada)
-often fairly delicate
-usually have a high cost per gallon (although at 1000L is amazing if true and it doesn't get clogged up along the way...)
-once used it remains wet inside with no way to dry out
-isn't as effective as some other methods

not saying it doesn't have a good use, just a limited one.