This from one of the Fresh Expressions pioneers doing missional church in the C of E in Devon, England...
The key question he raises is "What gathers a particular body into a sense of membership with each other?" If it's just worship style, that body, as such, isn't likely to be terribly missional-- it'll just be too tiring. If it's just missional stuff, it may be less than enthusiastic about worship.
That's his observation. What's yours?
And... as the title asks... what gathers folks where you are?
Peace in Christ,