I agree with Rusty about the unnatural braking. Despite having spent a lot of time behind the wheel of Toyota's hybrids (my own '04 Prius and my mother's '06 RX400h), I still couldn't quite get a feel to where the regenerative brakes would fully catch. Driving in traffic was a tad awkward because of it. The S400 is a big car, and powered by only a V-6 - even supplemented by the electric motor - it felt much too sluggish for a vehicle of its stature; I expect more oomph from an S-Class. Once going, it's, well, an S-Class: solid, planted, plush, yet still responsive.
The thing about this car is that I see this more as a way for Mercedes to create an "entry level" S-Class, but without actually going that route.
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