Product review (4 stars): Keeps the tower cold for less head on your beer.
I have used this cooler for a few months now and I can say it does the job of bringing cold air from inside the Kegerator up into the tower very well.  i can tell it works because the tap sweats on humid days. Mechanically as with any fan it can get frozen over if left too close to the cooling grates in the kegerator. Especially living in Phoenix keeping the tower cool is essential for cold beer and lower amounts of head, and if it can work this well here it will work anywhere.  The Coldtower works like a charm.

I only have two complaints about the unit and both of them relate to the power chord and switch.  One, the chord and switch are quite short, especially if you run your power for the unit in with the CO2 lines.  Ordinarily this wouldn't be an issue, but while moving the unit slightly the chord ripped out of the switch.  I have since soldered it back in place and gotten an extension chord but its something to be careful about.  My second issue with the power chord is that it would be nice to have an indicator of when the unit is on.  This unit is quiet and it runs on the inside of the kegerator with the switch outside.  The only way to tell its on is to open the door to hear it, or to pop the top off the tower to feel the airflow.

Even with the power chord issues, I would certainly buy this unit again.  I do and have recommended this product to friends.