I guess I would count as a #3 in Englishman's list. I left because I didn't believe it anymore.
But it wasn't merely a negative experience... it was part of a spiritual journey. Not some sort of overnight awakening, but a gradual process of growth.
I started this process before I left the JWs. It was really a process of recognizing the cardinal values of love and compassion. Seeing these things made me frustrated with the dogmatism and lack of love preached by the GB, and I think that played as strong a role as doctrine in my eventual exit from the organization.
When I left the organization, I still believed in Christianity and the Bible, and I felt that I was coming closer to true Christianity and the truth of the Bible than I ever had been before.
When I eventually moved away from the Bible, it wasn't primarily because of the scientific or logical arguments against its inspiration (although those were important) but because I came to realize that despite being a progressive book for its time and culture, it still, in many ways, taught intolerance and hatred.
Basically, the journey has been a gradual move from judgmentalism to acceptance. First, I started accepting my fellow Witnesses, even those who were "spiritually weak." Then I moved on to accepting other Christians. And finally, I moved on to accepting the whole world.
So no, I didn't have any sort of overnight religious experience. But I don't feel like I've missed out on anything, either.