Product review (4 stars): Expensive but worth it compared to 3rd party knockoffs
They're not cheap, but I've tried 3 other 3rd party filters and none of them worked right.  All of the other ones would cause the water dispenser on my Whirlpool fridge to hammer/knock and only spit out an intermittent stream of water.

This filter worked great from the get go with no issues in the last month or so that I've had it.  My wife said she noticed a taste, but I haven't noticed a difference beyond "different than tap water".  I've been happy with it, just wish they weren't so expensive.