Missional Vs. Attractional

So I've recently discovered a debate raging in the land of the Christian bubble. Which style of church is more effective in creating disciples of Christ. Disciples of Christ would be what we would like to think of as Christians. Those who follow Christ. What I'm running into is, how do we know? What I mean is, there are many "Christians" who attend church on Sunday and live a decent enough lifestyle, but aren't necessarily living the life of Christ embodied in their own life. The debate between the Attractional church and the Missional church is based around which is the most effective tool to create Christian disciples. Before we go any further, I'll briefly explaining the difference between the two.
The Attractional church is one that is Christ centered and is solid. It creates/mixes powerful worship services and/with programs to "attract" the outside world to their doors. This is the style of church most of the Western world is used to. It's probably what you attend if you attend church somewhere. They come in all sizes from small churches to mega churches.
There are some who believe the Attractional church will fade away and is only catering to a fading demographic. So, they suggest a Missional church is the answer. The Missional church is one that is liquid. That is, they adapt to the cultural/social surroundings and attempt to move in that culture. It exists in the culture, but without sacrificing any of it's core values or beliefs. In fact, the Missional church would say that living a Christ life in the midst of those needing discipleship is the only way to create true disciples...and they'd back that by pointing to Jesus as their primary example.
So again, the debate is over the most effective method. My question again is, how would we know? There seems to be a very thin line between an authentic Christian and the average church goer these days. Honestly, I know there are days that I myself would be in question. Again, a disciple of Christ is one who follows Christ's example and lives that out in their daily life. They're not someone who merely mimics Christ, but truly embraces a lifestyle like Christ. I'm positive both churches produce such people. However, there is the other side of that line where people are genuinely excited about church and the fellowship, but they haven't quite caught the concept of embracing Christ in the totality of their lives. I believe both churches are producing these people as well.
For me, I think both churches provide a need to people. I think the attractional church is actually fluid if it's what the demographic of that particular area needs. However, I also find the idea of the Missional church to most closely represent Christ's life through his church. So I also agree that the church should be living amidst the very people it seeks to impact. But, even so, that doesn't answer my question within the debate. How do we know which church is more effective? Maybe the answer lies in both.