My 'un-testimony' did not deal with D'ism:
While a grew up in a Dispensationalist futurist church, the main reason for leaving that kind of thinking was triteness, soundbytes, and crassness. When you get tired of that and want to see actual thought go into a position, you probably won't be D'ist. I found satisfaction in reading Lewis and Schaeffer on many things, and found that the churchfolk just did not know what they were getting at, so it was too hard to pretend that they had a real handle on what the NT was saying.