Dennis used to be my mom and dad's pastor before he went into full-time evangelism. I was in college at the time, but then I worked for Bro. Boyd for a while and got to know Dennis and Cathy pretty well (I was at their wedding). Good people.
I heard him about 20 years ago when I was in Texas. I heard him about 15 years ago in Indiana and I've heard him maybe other times. He has grown spiritually I think because his preaching seems to have a power it didn't 10-20 years ago.