I reverted mostly because before, as a Christian, I was always taught that when you prayed to God you had to feel some close connection with him. However, I never did. So I pretty much grew up thinking I was a failure - a horrible Christian, and that God must hate me or something was wrong with me because I couldn't feel what everyone else was. But after I started reading about Islam, I prayed and actually felt like there was a God and like he was actually listening.
Christianity seemed too easy to me. I was taught that once you accept Jesus as your savior, you ask his forgiveness if you ever sin and you're automatically forgiven - free to do it again and again. That didn't seem right at all. In Islam, God is fogiving and merciful, but there's no way for you to just sort of do whatever you want and still be "OK" in the end.
Also, the fact that there was absolutely no guarantee the Bible was accurate at all was a huge turn off, and I liked that the Qur'an we read today is the same it was hundreds of years ago when it was written.
To me, Islam is everything I liked about Christianity, and everything I wished that Christianity was. There's nothing that "just doesn't add up" in Islam like there is in Christianity. I saw a video of a talk with Yusuf Estes, and he said something like, "When I converted, I felt like I became a better Christian because I was following the religion of Jesus." That pretty much sums it up.