Delta 9 Welcome to the forum. Whilst information is changing all the time there is some historical information in the FAQ at the top of this Forum.
Please bear in mind that, when on board a commercial aircraft as a passenger, you are legally bound to follow the instructions of the Cabin Crew. Wiggy in post #10 said it: If asked to turn off the unit = DO SO! Without delay or question.
By all means give feedback here after your trip. The thread will slide down the timeline and you can check subsequent pages for it, or search for it.