Here is a video that gives a pretty basic description of the missional church. Admittedly, it doesn't cover all the nuts and bolts of missional ministry, but, as the title suggests, that is not its purpose. When people talk about the "missional church," it can sometimes come across as being overly critical of "other" churches. I could see how people who are invested in attractional ministries might take offense to that video even though I don't think it was attempting to be critical.
Does it have to be an either-or thing?
Maybe attractional ministries can still bring people in to hear the message of Jesus Christ while people are going outside of the church walls to share the gospel.