I totally love my Whoosh Crusa & it has been totally perfect for what I bought it for. & for a person with a disability that hasn't ridden a boke for 20 yrs - I have done over 350 miles in 2 months!!
However my teenager has her greedy little eye on it & with the prospect of communting to work on a bike I wondered if there was something as comfy as the Crusa but that weight a lot less!
An ordinary bike weighs about 14 kg, a battery weighs about 3.5kg, a motor another 4 kg , a controller and wiring another 1kg, so an overall weight penalty of 9kg for electrifying a bike. Typical well speced road worthy ebikes are up to 23kgs. It costs a lot of money to reduce weight, exotic materials, carbon fibre. It would be much more cost effective to cut out a latte every day and reduce the humans body weight by a kilo than to spend 1000£ on reducing the bike by a kilo, and one would feel better anyway.
Anyway the only time the cyclist on an electric bike need worry about the weight is when they are struggling to carry it up steps or through doors. Normally the power of the bike more than compensates for any additional weight....the cyclist will normally weight 3 to 4 times the bike
.. I was going to say don't sweat it... .