I honestly have never used any kind of strike indicator on any of my carp leaders. For me, it is almost like a “sixth sense” that indicates when the carp has actually taken the fly. Sometimes the body language of the fish (if water clarity is good enough) will give it away. A slight turn toward where you feel your fly is, a little tail twitch or the bright orange color inside a carp’s mouth all can be subtle hints. I very rarely actually feel the take but any kind of unnatural movement of the leader can indicate a take as I usually try to keep a tight line between the fly and where my leader is breaking the surface. If the water is too murky to see the bottom when my leader slacks up a bit indicates the moment that the fly has touched the bottom.
I’m very curious and hopeful that we get responses from anybody who has had any experiences using a strike indicator system while flyfishing for carp. Great question and topic!