spike-2 ..............
An intermediate line can be a welcome addition to your arsenal. On windy days it will cut through the wind while casting much better than a floater. You will find that you can cast much farther with an intermediate which means more time for the fly to be in the water in the strike zone.
On wavy days the surface waves will not interfere with the action of your retrieve.
There are many benefits.
Hope this helps,
DickM.