Product review (4 stars): Water flow decreased significantly, but an easy solution exists.
Although this filter states it filters more that its PUR counterpart, it does so at the expense of a significant loss in water pressure and thus the speed of flow.  I'm quite disappointed.

UPDATE: Ok,  after fishing 6 to 8 gallons through the filter (Whirlpool recommended a 4 gallon flush) no change in flow.
BUT, I think I found a solution. I stood the filter upright in the sink and added cold water slowly to allow all the air bubbles to come out.  After a while, all the air was finely out. I reinstalled the filter and the flow is acceptable.