Parkway has dwindled down, as was mentioned. Their founding pastor Frank Tamel just passed away earlier this year (or late last year).
His son Tony is now the Senior Pastor. Lots of waves, ripples, and gossip abound about the current state of the church. I'm not in the know, so I can't say what has been the cause of the loss of membership.
As for Madison, it hit high marks in the early 2000's. A massive inner city outreach and children's campaign flooded the church with new people.
They were using nearly every auxiliary room and Sunday school area just to accommodate everyone since the sanctuary wasn't big enough.
The Senior Pastor John Grant is ailing; his son Roy is pretty much handling all of the pastoral duties now. There is a plan for a new, much larger building, but I don't know where things are on that end.
(And btw, I guess it's called Calvary Gospel, not Calvary Tabernacle.)
http://www.theoakcreekchurch.com/
http://www.calvarygospelchurch.org/cms/