We got the Coleman Thermocooler and used it for about a year. Its good for keeping drinks cool. As for food, if we stop during the day to pick up stuff for dinner that evening it is also good. If we got stuff for breakfast the next morning it was good enough but that would be as far as we would go with it. Of course we are talking spring and fall in the mountains. During the summer it just can't keep things cold at all, only cool. Also, air is blown in to keep things cool. If you load the thing up it will block the air flow and stuff at the opposite end will not be as cool as by the air outlet.
We just got an Engel 32q and the first thing I noticed is the power requirements. Our daughter used the coleman on a trip and one morning found her battery dead. We regularly leave the fridge running for 9 hours and the Jeep fires right up. Overnight we set it on 1 and 1.5 during the day and everything is cold. Setting 1 is around 50 degrees while 1.5 is around 46. We don't worry about food being in the fridge for a couple days.
The only advantage of the coleman is it is a 40 quart while the Engel is 32. But, we don't have to worry about how we load things in or how much we load. If the lid will close it will stay cold. The fridge is heavier, not by a whole lot though, but is just as easy to get in and out of the vehicle. If you do get an electric cooler you will want a fridge after a short time. Just go with the fridge, it will save you money in the long run (buying the cooler then a fridge, and wasted food).
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