We have a split unit Whisper Kool and it has been trouble free for ten years.
We do the annual check ups and have had to replace a capacitor on one occasion, but otherwise care free.
Our cellar is below grade, so I don’t think it has to work too hard, but we keep the cellar at 53% without breaking a sweat, even when it’s 100 degrees + outdoors.
In the cellar, we have a little control pad and keep the thermometer inside a wine bottle filled with water. Other than that, vents come in from one part of the system and the compressor (the thing that makes noise) is out by the HVACs for the rest of the house. I hear nothing in the way of noise.
We also have a small ceiling fan in the cellar to maintain circulation, humidity naturally runs about 62%, so we leave it be.
Put me down as an endorser of Whisper Kool. (Our wine cellar builder says it is his preferred brand, as well.)
I had a thru-the wall whisperkool, which worked great until my contractors did some work on the cellar. Since that time, I have moved on to a different getup, but I enjoyed mine while it lasted. And it looked cool.
I had actually spoken with Chris a while ago but as I had not hired him for this particular project (mostly given that his services are more geared toward soup to nuts construction and he is too remote from my location—although he did offer to work as a consultant) I was uncomfortable pinging him about this issue.
To be clear. I was just trying to be funny above. Chris has been super helpful to many on this board building a cellar, including me. (I’m also comfortable with his BTU suggestions. But I live in a swamp, and summers are HOT.)
I went with a Cellarpro thru-the-wall unit for my small cellar. I gave them the dimensions and the insulation numbers and they came back with a sizing recommendation. The cellar stays at 55 year round and I have zero complaints.
Since that time, I have moved on to a different getup, but I enjoyed mine while it lasted. And it looked cool. 
