Down-Rigger Trolling is a situation where the bites can be hit or miss and there are dry spells.  With the strikes sensor you are all ways on top of those light biters and the hits before they release the clip.

You can down rigger fish with the sensor with the rod loaded and still see the strike without relying on the line pulling from the clip.  This allows you to use multiple rods and keep your lines tight to the clip and monitor biters and shakers.