Product review (5 stars): obviously - like when Jiffy Lube tells you to change your oil ...
Pricier than the generic brands, but from other reviews (black water after installation) I decided to go with the genuine article.  Works perfectly, clean and clear from go.
I recently had a repair on my icemaker, and the technician told me that it is not necessary to replace the filter when the light goes on.  It is just on an arbitrary timer, and usually goes on earlier than actually needed (to sell more filters, obviously - like when Jiffy Lube tells you to change your oil every 3,000 miles when that is totally unnecessary).  He said to keep using it until the water flow is diminished, that's the true indicator that it needs replaced.  I'm going to go with that advice, will definitely save some money.