Product review (5 stars): Not worried about NSF
This couldn't possibly be easier to install. I just popped it in and could hear the water filling it immediately, worked right off the bat, no problems since. I don't notice a difference in water taste from the original GE filter.
It was useful that it came with stickers to put on the filter to remind you when to replace it (6 months). My original filter didn't even have a space for that!
As for the whole NSF certification thing, I do doubt that a company would make false claims about having a certification especially when penalties for misrepresentation are pretty high and can tarnish a company's reputation forever. It is a pretty big accusation to throw at a company saying that they are not certified unless you have irrefutable proof, which I am not so sure a lot of these reviewers have.