I have the biggest Truckfridge (TF130) in 12V and like it a LOT. Although there is a dual voltage version (12&120V) I went with the cheaper 12V only as my Scamp
has a (brand new) 120 to 12V converter so I saw no need for the fridge
to be 120V capable.
I can't remember the specs right now but I was a little surprised at how much it runs and how much juice it draws. To be fair, we have the door open a lot, it is a larger unit than we had to have, and I run it colder than required. But I wanted the larger unit for longer trips, plan on solar to recharge the batts, and in State Parks we have 120V anyway. I should mention I added as much foam around the sides, back, and top that I could in the space provided without blocking air flow over the coil. The running noise is noticeable but not bad and does not bother us at all.
It is so nice to be able to plug in at the house a day before a trip and having a VERY cold fridge to start out. Then it runs fine under way, and again at the site whether plugged to shore power or not. This seamless transition from house to road to camp and back is a BIG plus to me, not having to mess with a propane
My goal when I installed this fridge was three days without charging and without dropping below 50% capacity on my dual 6V batteries. I have not been camping enough, or tested it scientifically enough to say with certainly if I have met that goal. My feeling is it is achievable but we are in and out of the fridge too much and I am running it too cold. I have other loads such as a CPAP machine that have to be met also.
I have not installed my solar system yet, but others have done so successfully so I feel in the end I will be fine with the Truckfridge and solar for all our 12V needs.
I do think that most people would be better served with one of the smaller units, or even one of the chest types. The front door versions "dump" a BUNCH of cold air every time you open the door causing the thing to have to run to make up that lost coldness. Also, one of the portable chest types could be put in the tow and ran while you are out and about from camp.