I visited one a few times, but I don't like crowds in general. All that energy can be overwhelming. The last time I went, the preacher was leading the huge congregation, along with them people watching at home in prayer and he said said something that disturbed me. "And, God," he said as everyone repeated, "please teach me to forgive today." I about crapped my pants. Here's why: after we left, we went to a restaurant and the waitress was being nice to everybody in the place but my wife. I tried to keep her calm, but she kept getting angrier and angrier. As we left, she told the waitress off very loudly and decided to forgive her once we got in the car. Then I reminded her that she asked for it in prayer.
There's no telling what other unpleasantness the thousands of people praying along experienced. I sent a nice little email to the pastor about it, but never heard back. Go figure.