As someone who has had both a physical death experience (flatlined, no heartbeat for several minutes) and psychedelic-induced death experiences, my experiences of the two were quite different.

Physical death for me involved no "white lights" or life-flashes. It was just pure, black nothing. Like a dreamless sleep -- you go to bed, and then next thing you know you're waking up. Everything in between was a blank, black nothing, with no sense of time.

Psychedelic death experiences were a thousand times more intense and I still retained some element of base level consciousness.