I am looking into upgrading next year to get more range and 32km/h instead 20-ish real km/h. Currently, because budget oriented, i am looking into Gotrax G4, and for more range, Gotrax Gmax. But then, we are getting into the territory of Fluid Freeride (17.4kg), Zero 8 (17.7kg), Apollo Air Pro (17kg).
My Gotrax XR Elite (look at the dimensions) seems fair enough with 12kg and being able to be stored ok.ish. 10cm wider, longer, seems ok, too. (i am not advertising Gotrax if you have the budget for something better and want something called “service”)
I guess, you need to judge what weight you are ok with, and lighter is better, but smaller easier in an apartment/stairs. Also, your range, i would not plan with that range, minimum double.