Wow, lots of back and forth on this, and no I am not going to read all of it.
Both the Norcold and Dometic fridges are great. The reason people have trouble with them, is not the
fridge, its usually the installation. Proper venting up top, and I mean, not too much venting, but proper venting, it has to act like a chimney with a draft. Fridges in slide outs with a upper wall vent also are problematic as they don't get a good draft either. Norcold installation drawings are pretty clear about having baffles that force the air into the coils and the top of the coils being open. Few RV manufacturers get it right
I have had two Norcold 611's which worked great (just be sure and install the door bottom hinge reinforcement kit). I currently have a Dometic 2652. All were/are 6 cu ft
fridge freezer with separate doors and compartments. They both get good and cold on
propane or electric in the summer heat of the southeast. I tend to like the Norcold a little more, I think it is because I seem to be able to get more in it, but not sure. I do not like the external drain setup on the Dometic so I installed a aluminum catch with double sided sticky tape in the compartment and ran the new drain hose into it. The Dometic drain hose tends to become crumbly and I didn't want to use clear plastic tubing due to its close proximity to the hot pipes.
If you are unable to get the proper draft on the backside of a
fridge, then fans are a cure, but at the expense of
battery power. They are almost a necessity on fridges with the upper vent in the sidewall.
The other problem is air circulation inside, they need to have a space BEHIND the food so the cold air can descend to the bottom of the compartment.
I have read of several people having poor performing fridges and after they removed shelves or compartments above the fridge that were blocking the flow (backside above the fridge, not the inside) and then creating a tapered chimney from some sheet metal, the fridges worked fine. Its not much different than a oil
furnace or wood stove that doesn't draft properly, vs one that the air flows thru correctly and has just enough restriction to keep the chimney from over drafting.
Charles