Both of these cars are heavy compared to the BMW i3 at 2700 lbs. The Leaf is about 3300 lbs and so is the Benz. But, none of them are a leap into the future simply because the current traction batteries are expensive, heavy and low in energy density; that causes the auto makers, even with sales incentives from the States and Federal Government, to compromise in order to sell the car at a price point acceptable to buyers.
Of the three cars, BMW is the one moving in the right direction by reducing weight and friction and improving aerodynamics while waiting for the next generation battery. And, of all the car makers, Tesla is the only one concerned with the health of the Planet instead of counting their beans. Nissan has been at parade rest for four years happy to sell a limited range car and to wait for the others to catch up.
