I joined a church plant within a month of it "opening" in my local city. It was a non-denominational (but reformed baptist in doctrine). Our church plant ended up planting another church 5-6 years ago in yet another city in our area. The planting church is part of the
Acts:29 network which helps facilitate church planting.
One of our elders told me that we would never be a mega-church. Instead, when we grow to a certain point we will take some of our families and plant another church.
We left that church this past year to join a Southern Baptist (but reformed leaning) church that is closer to our home and is a little more traditional and liturgical. The church we now attend is also part of the Acts:29 network.