I use the green 14 lb test Fireline for several reasons.

1. It's high vis.

2. It will always be stronger than the leader I'm using so in case of a snag, I never lose my float.

3. Small diameter.

4. It floats. It's easy to mend the line without disturbing the natural float of the bobber.

5. Unlike braided lines, Fireline doesn't have the tendancy to wrap around the tip of the rod.