I just got a comment on my post about finally reading the book The Boy Who Came Back From Heaven from a Pastor Ken Burkett who included a link to a sermon he gave on the subject of the Heaven stories.
From about a third of the way into his sermon he covers so many solid biblical points it seems like a very valuable resource so I decided to recommend it. He mentions many books that have come out in recent years on such experiences, more than I've touched on here. He also confronts many of the logical problems and contradictions between the various accounts as well as with the Bible.
He acknowledges that there's no reason at least in some of the cases to doubt the sincerity and honesty of those who had the experiences, but he stops short of suggesting that therefore it had to be a spiritual fraud concocted by demons. I think it's necessary to draw this conclusion myself, however, because people do need an explanation for how the people could be sincere but the accounts be false.
The whole sermon is a good overview of all the problems involved in these extremely popular accounts, and his perspective is thoroughly Biblical. He concludes that if people read the books and don't see contradictions with the Bible they just don't know the Bible and need to put down the book and go back to the scriptures.
That's the problem with this whole phenomenon right there.