Our KA will be 2 years old in a couple more months, and we really couldn't be happier with it. We use it for wine, beer, and mixers for the bar. We chose it because it was one of the only models that had three wine shelves instead of two- that was important to us because we consume more wine than beer. We also find the three-zone cooling very convenient b/c everything is at the correct temperature right out of the fridge.

Minac, you have email! For us, the main attraction to the KA model was that it had three wine racks rather than the two that most other brands had. Originally we were looking at wine coolers, but as we considered how our kitchen may transition when we had kids, we decided a beverage center was probably a better choice. We also liked how the KA had three zones (beverages, whites and reds) and how the beverage part got colder than 40 degrees (it goes down to 37). That's important for cold beer and also if you want it to be food safe for storing open juice etc. The unit is really quiet; the compressor is hard to hear unless you're actively listening for it. When it was new, I could clearly hear the relay that triggered the compressor. It made a single twanging spring noise everytime the compressor kicked on. I thought something was wrong and KA sent a warrenty repair guy out. He checked it out and said it was normal. He also explained how different types of relays work, and how the kind I had was louder, but much more reliable, and that with a bit of time it would become quieter. And it did. Now its very rare for me to be able to hear it.

The wine storage will be cooler. If the area outside of the wine storage will not be high humidity, you don't need a vapor barrier. You want to stop air flow and insulate. Fiber bats will not stop air leaks. Spray foam will.

R 13 isn't really great insulation. In addition, the Whisperkool unit isn't designed to vent to the outside. Cooling units are designed to operate within a general range of temperatures. So a fridge, an AC, and the Whisperkool unit are all designed to operate within their own unique parameters. An AC unit usually goes 25 degrees or so and expects the top temp to be somewhere in the 90s. So you get cooling down to the mid sixties or so. They don't get things quite as cold when the exterior temps are in the high 90s or 100s. A fridge is designed to cool down to the mid 30s or so, and to operate in an ambient temp of around 70. That's way past the condensation point, so you have really tight seals and super insulation. The Whisperkool is designed to cool down to about 55 or so from an ambient temp of around 70, not the 90s you may experience outside. It's not rocket science tho. If you want to get cooler, you need a larger evaporation coil and a more powerful condenser and you help the machine with tighter seals and better insulation. Thus, you can leave your door slightly ajar with a window AC unit and you'll still get fairly cool, but you wouldn't leave the fridge door slightly open. To your main question - the one degree fluctuation is not all that bad. Don't sweat it. To your larger question that you didn't ask - you're possibly overtaxing the Whisperkool unit. If it dies on you, you can replace it with a regular window AC unit. Just seriously oversize it, then tweak the thermostat - either replace / bypass it, or tape a resistor onto the probe so that it thinks the air is actually warmer than it is and it cools a bit more as a result. It's how I cool my wine cellar.