Product review (5 stars): Works just like the OEM
I wanted to purchase a filter that was equivalent to the OEM, but much cheaper.  I was concerned with the NSF ratings, as NSF 42 makes water taste and look better, NSF53 takes out more contaminants.  Most of the bargain brands do not come with the higher rating.  For this brand I chose the deluxe model for the higher certification.  It is still less than half the price of the OEM.  From what I can tell, it works just as well.  My water is clear, and my cat actually likes the taste of the water out of this filter better, which means she'll hydrate more.  I had no trouble with the fit and no leaks.  I was really concerned about misfitting & leaks, as I once had a very bad flooding incident upon changing a filter that didn't seat quite right.