I don't think that's an e-bike - the Solex has been around for many years in France, uses a small petrol engine and a friction drive to the tyre. There is a rear-wheel variant too if I remember correctly.
I think the weight of an engine over the front wheel would make the handling a little strange, at least until you got used to it. Friction drive wouldn't be suitable for a true e-bike IMO because it's not very efficient, and you wouldn't want to waste what power you have from a battery driven system.
An electric motor can give a great deal of torque from rest, and unless you rode carefully you'd get lots of slippage. I hear that's a problem with the Solex system too if it's wet.
Rog.