I agree with 999zip999 on this. Some people want 2WD simply because they want it. Others might want 2WD because lots of snow, etc...I think a 2WD is a great starting point for building a stealthy ebike.
I would never recommend a very powerful motor on a front fork (a few forks are strong enough for high power, most are not), so...any motor on the front should be a lower power unit. Once you decide on a modest torque level, a geared hubmotor will be smaller and lighter than Direct Drive.
The rear can be a geared hubmotor, or a DD hubmotor (DD would allow regen braking). I recall ES member Kepler building a carbon road bike specifically to be stealthy. He started out using his expertise in RC motors to add one of his RC drives underneath the BB...practically invisible. However, there was no practical way to make it run quietly. He ended up using a small geared hub on the rear with a sine-wave controller. Very quiet. The hubmotor was about the diameter of the disc brake, so between the brake and the sprocket cluster, it was very stealthy.
If I was building a stealthy ebike, I wouldn't want a physically large hubmotor on the front, but fortunately, we have quite a few small geared 250W-rated hubs available (which are often run successfully at 500W?). Using 500W on the front, and maybe 900W on the rear doesn't sound like a hot rod (1400W?), but...it's actually not bad for an ebike that doesn't even look like it has motors...to the casual observer.
Pic is a Cute Q100
