Have done this. Do not put it in your suitcase under any circumstances as if it gets damaged or stolen you are responsible!!.
You can use the DVD player on the aircraft except for take off and landing. Check with the airline in question re their policy though. Generally speaking policies re electronic equipment are the same across the board.
We took ours on the plane, godsend with ryanair as they don't exactly have seat back tv's .
Due to the weight you really wouldn't want to put it in hold luggage.
We used it everynight on holiday as it was to cold to sit out and the kids were a bit young to be out roaming about later on, so we watched a movie every night, and once kids were in be d we watched another one as there wasn't a telly anyway.