Glenn Greenberg said that the spidey office was seriously considering having Ben Reilly assuming both the Spider-man identity and the Peter Parker one with both Peter and MJ's blessing. So they were literally going to make him fully Peter at one point. Now, obviously you can see how much trouble they would have had in doing that.
There is a reason Ben Reilly was liked (one of the few things out of the Clone Saga that was). A lot of care was put into developing his character so that you couldn't help but root for him (admittedly this was done at the cost of tarnishing Peter a bit). He was Peter in all the ways that mattered, but he was distinct enough from his five years travelling to be his own person. The only writer who truly knew what made the guy tick was Dematteis (which is why he should have been the one to do the Scarlet Spider book post Clone Conspiracy).
Personally, I felt Ben should have stayed dead. I was fond of him as a kid, but he died a heroic death. His legacy cast a long shadow and added extra fuel for Kaine's ongoing development/redemption. Now both characters are in limbo. Which is a shame.