Bret13:
Well, I have a ARB version of the Engel. I really like it. Here is how I use it:
For short trips or trips with one or two people, i use it as my main cooler. Fill it with everything, including frozen stuff that will thaw and help keep stuff cool and use less power. I really like the removable basket. I plug the frig in the house the day before, then move it to the camper. Place the basket in next, so it is not so heavy. I can also start it the night before in the camper, as usually I will be driving the first day and so will charge the batteries. I have two batteries....starter and a deep cycle second battery just for the camper and toys. It is under the hood. No solar....yet.
If I don't have a lot of passengers, I place the fridge in the back seat of my extended cab. This way, maximize space in the camper. I can reach through the sliding window into the cab to get what I need. Another reason for the sliding window!
If I am going somewhere with a lot of folks, I can be sure they will all have coolers. This also holds if I am going on extended (more than week) trips with little chance to resupply. I use the fridge to freeze food and cold packs. I can then change the cold packs into the ice chest to keep food cold and don't have to get ice. At least I don't have to worry about getting ice. Others will. They can travel.
Now, I can run the fridge in fridge mode for about 3 days on the 100 AH battery pretty easy. If we are driving every day, no problems with the freezer. Have yet to try the freezer in the hot desert.....one day I will. I think that having solar could really help. I have a 28 watt panel and it will actually run the fridge when the panel is in full sunlight. Amazing.
To answer your questions:
1. Yes, great for weight savings.
2. Powered from batteries when not moving. Never had tried an extended trip where we stay put. Expect about 3 days power.
Other findings:
My brother has a northstar with 3 way fridge. His is much bigger, but will kill his battery in 1 hour!! AC is nice, but how often do you have shore power (seems FWC users rarely do) Propane is cheap, but I have a shell and don't want to worry about propane tanks. Besides, those units must be level for the propane to work. Switching back and forth when stopping for anything more than a few minutes is a royal pain. There is also the Two-zone from down under. expensive, but might be nice to have the freezer/fridge combo going. One day I might try it.....
Also, get he case. I took it on the maiden voyage on some rough roads in Hell's Canyon. Boy did it get dinged. Also, the Transit lock option and secure it to the camper or truck. Don't like to see that expensie box jumping around in the back......
In short, espensive, but really convenient and fun to have. Don't leave home without it now. All my friends want one. If FWC/ATC could figure a design to have these built in......now that would be cool....
Good luck and let us know what you find.
Dave in Seattle.