I myself have been in both. I was raised nominally as a Catholic. I was a fundementalist for a year. Then I became evangelical Protestant. Then I became a minister in a fundementalist denomination for a few years.
The most disconcerting thing was their lack of love. As an evagelical minister in a fundementalist church I tried to make them more evangelical. I had some success. I had them reading the NIV Bible instead of the KJV. But my non-fundementalist Christian friends warned me to get out. There were right. But I felt I had to stick it our because I was single at that time, and its extremely hard for a a single man to find a pastorate in Protestant (the exact opposite of Catholicism). So beggars can’t be choosers.
Towards the end, the members were complaining I was “too liberal”. They were shocked that I believed that a good Christian could drink wine now and then. A woman was in tears when she found out that I did not consider it a sin for a black man to marry a white woman. After three years, I was told to resign. What hurt me the most was that the ones I was closest to instigated this. When I asked a woman who was like a mother to me how could she betray me, she said it was more important to be God’s side than on my side, since I was blinded by Satan.
I was devastated. I was in my thirties, and I knew it would be difficult to find another pastorate. Anyway, my spiriual life was destroyed, so I was no longer interested in the pastorate. I married a Catholic, and went back to the Catholic Church. It was there that my love for God came back, and I learned to forgive those who hurt me.
Fundementalists remind me of the Pharisees. There is not much talk about love, forgveness, humility, or tolerance. They pride themselves in standing for what is right as they see it. But there is a lack of compassion. They are quick to judge others. Anyone who does not see things the way they see them is of Satan.