I have two Igloos and a Coleman. They are definitely not refrigerators, but they work fine for keeping things cold as long as you have a lot of battery capacity or charge your batteries frequently, and the ambient temp doesn't get too high. They are big time ENERGY HOGS. Mine will drain a battery overnight. The best of the three is the Coleman, and it will cool to a little over 40 degrees below ambient. The other two will do about 30.
There is no comparison between a thermo-electric cooler and a refrigerator. I use the thermo-electrics for extra capacity when using an RV, where I have unlimited electricity. For backcountry travel I use a real refrigerator.
To clarify a little, I started out with an Igloo thermo-electric back in the early 90s, before I knew the refrigerators like Engel and ARB existed. Maybe they didn't exist then. It seemed like a big step up from floating, soggy food and continually buying ice. After moving up to a refrigerator, I would hate to have to go back to the coolers. If I were starting out today, I would bite the bullet and start with a refrigerator. It is cheaper in the long run, and far superior.
JP