In regards to the weight, I'll refer to Elizabeth Moon's "The Deed of Paksenarrion" where she spoke about wearing a helmet all the time....."it strengthens the neck muscles.....makes it harder to cut through". After a while, with the right padding, you forget you are wearing it.
We will definitely pad our helmets! And parts of the other armour. It just fits better, and if it stays in place, the fiberglass won't rough up your skin..
We got big Lipo batteries, and spares for them xD