I really like the B mode. It gives me the feeling of driving a manual transmission again, which is my preference. In my auto ICE cars I am always downshifting to engine brake and keep the engine at the best RPM for power when speeding back up, as I would in a manual. No, depending on regen is not the most efficient way to drive but where I drive, with lots of traffic and unexpected slowdowns, it feels right, and I love the fact that at least SOME of the energy I would have otherwise wasted braking is going back into my batteries. I would like to be able to adjust the amount of regen but how Nissan has set it is pretty good.