The kit I got for my private pilot (part 141 school, Jepp kit) contained an E6B. I looked at it, gave my instructor a funny look, and his reply was "If you don't like it, buy one of the electronic ones." My instrument instructor showed me one day how to use it, but I've forgotten.
My DPE didn't seem to mind me using the electronic one, and it was ok to use on the test (I bought a Sporty's electronic E6B).
Yes, I carry spare batteries for it, in addition to spare batteries for the mini-mag. My outlook is if I'm in a situation that I'm having to use the flashlight, the darn electric E6B will choose that moment to die, so better to have spares for it to