Product review (5 stars): Seems to work well
The PUR filter that came with our Whirlpool refrigerator lasted us about 5 months before our fridge directed us to replace the filter.  I balked at the high price of the PUR and other retail-priced replacements and found this 3-pack available on Amazon for under fifty bucks at the time I purchased it.

When I replaced the filter, there was some water leakage around the new filter.  I fiddled with it thinking I had installed it improperly, though I think I had it installed correctly all along.  It seemed to self-correct after about 5 minutes of running the water and wiping up the ever-decreasing amount of leakage from around the filter.

Weeks later, a repairman was at our house to repair our oven, and I asked him for his thoughts on why the fridge filter leaked when I replaced it (note that he is a subcontractor familiar with the inner workings of just about every kitchen appliance).  He indicated it is normal for there to be some leakage until the new filter fills with water and the water and air that were in the line get flushed through.

So if you have leakage issues around the filter seal immediately after filter replacement, give it a few minutes and run the water to flush out the line and make sure that the new filter has a chance to acclimate.

The filter has been in service for about a month now and is working fine and does not leak.