Sadly, not always for the better. Someone I knew well had one in the form of a panoramic life review which eventually led to his mental decline and suicide.
That's interesting (of course I have no direct experience) but most of the literature I have read they come back a lot more spiritual and at peace with the way things are I have not really read any negative ones apart from immediately after when some people are quite resentful at being brought back
The person I knew had a car crash. The vehicle went off the road and rolled sideways. In a flash he saw all the best parts of his life so far - happy childhood days, girls, sunsets on tropical beaches, all sorts. It was as if he'd never be so happy again, he told me, and soon afterwards he was dead.
One can kind of understand the reasoning, having a glimpse of paradise (so to speak) that could never be repeated in this earthly form
