[87maniac]

Weight is a Huge factor.

You'll feel it most at the end of a long exhausting ride,

-or worse, when a malfunction turns it a 'non motorized' boat anchor
and the motor assist/driveline will no longer turn the rear wheel,
you have to push it all the way back
where you parked your rig with the bike rack.

- A removable battery is Very helpful.
(try lifting 65lbs up to rack height w and w/o battery.)
- The lightest frame available is ideal.

Invest in a high-quality HD bike rack!
Caution, most off-the-shelf 1 1/4" receiver hitch will flex and bend.
I use a custom HD 2" hitch bolted to the frame. when loaded with
two full suspension ebikes, I can jump up and down on the rack with
no flex, rock solid!