Yep. The E-bike guys say their main advantage is more in not having to change brake pads as often.
(5 to 15% more range. See video)
More for
Everyone:
Cars, being more aero, with higher velocity and more weight, are better suited to regen.
Ek = 1/2mv^2
NB the velocity squared
Trick is getting that kinetic energy back into the battery. Ek = 1/2mv^2
Although I'm no expert, I always think of parallel SuperCaps (and buck/boost etc controllers) in concert with (smaller) batteries.
They can take the amps and being low voltage; can be fed charge at the lower rpms where regen is normally ineffective.
But there's power to weight, cost and complexity to consider..?
As nothing is as efficient as freewheeling this is the most elegant/brilliant solution I have come across:
Once the penny drops here; the Ah-hA! moment/s are worth the video! Simply Inspired! 
My research pointed to a
~20% efficiency boost from freewheel + regen IIRC.