Product review (5 stars): Easy, convenient
My refrigerator has an ice maker, but no built-in filter.  For years, I had been buying the snap in in-line type, but the prices have been creeping up and the availability has been diminishing.

This Culligan model has them beat. The price is good, it's easy to install, and very easy to replace cartridges. If you have an existing plastic water line, installation is trivial. This also works with copper lines, and is not much more difficult to use with them, except the instructions are not clear. The outside box says you can use either copper or plastic, but the included instructions don't mention the copper, or the additional tools needed to file the edge as the outside box mentions. Despite this, installation is trivial enough that it's not likely to be an issue.

If you do have copper, and need to fit things in a tight space, you might need to replace one end of the tube with plastic since short lengths of copper are relatively inflexible.

I also got one for my instant hot water tap on my kitchen sink. It's not "specially designed" for it as are the ones that are recommended for those, but they all take the same size tubes and have cold water coming in and going out. This one is far cheaper, does everything I want to make the water taste good, and there are enough Culligan options for anybody who wants a different level of filtration that you can pick what you need.

UPDATE:
Two years later, I removed it. It was not that there was any problem, but I installed a whole house filtration system and it was no longer needed. That showed me two things: First, the taste of the water did not change, meaning the Culligan worked just as well for me as the far more expensive system, at least with respect to taste. Second, it had been slowing down the flow of water on my instant hot water dispenser. The flow was noticeably faster without it, but I would not consider the slow down an inconvenience at least with respect to filling glasses or cups. Filling a pot of water is a different story, but the difference is understandable and what should be expected with this type of filter.