Putting anything on any fly rod except a fly, in my opinion is "WRONG".
For me and a lot of people might agree with me is that when i throw my fly rod, its for the ultimate rush, "THE GRAB". there is nothing else in my experience that satifies me more than when a steelie grabs that fly.
You not looking for the rod to bend or your bobber the go down. Just wait for that feel when that fish takes the fly and sends a rush of energy through the line.
just my 2c's