As seen above, the cobalt is 1245 lbs unloaded, and the evolution E1 is 2260 lbs unloaded. The E1 is just under 4ft longer in total length while closed, and 7 inches wider. So matching the trailer to your tow vehicle and driving/camping habits is important. I like some of the features of the E1, but the fridge is not a benifit to us. Alot of our camping we do borders Yellowstone Park and is prime grizzly bear country. Storing any food in a canvas sided trailer is a no go, and cooking in or directly next to the trailer (outside boiling water or maybe soup, etc.) is not wise. Outside shower would be handy, but we are going to try one of those gravity fed solar showers, provided there is sunshine. I feel once you have the E1, going to the cobalt would be hard to live without the amenities, but when going from tent camping to the cobalt, it is like a luxury suite!