Hey guys so I am thinking about changing my mainline on my carolina rig rod from braid to fc. However I have never used fc for anything other than cranking. I love braid for the sensitivity, but where I am fishing is very rocky and I am having to retie more than I would like. I am worried about losing a lot of sensitivity though, how close are the two lines?   thanks!

I don't use braid/superline for many presentations but Carolina rigging is one of them.  I use 3/4oz weight usually.  Braid casts much farther and has lots more sensitivity than any other line in this particular application.  The heavy weight pins the rig to the bottom and any bite is felt as a definite pull on the main line.  Since bites can come at the far end of a cast, the no-stretch of braid makes a big difference in the ability to set the hook at long distance.  I prefer fluoro for most bottom presentations but this isn't one of them.  My C-rig reel is spooled with 20lb Fireline.  It works great on a C-rig, handles well, and the cost is moderate.

The sensitivity and low stretch of braid makes retying worth it when C-rigging imo. 

I used 20 lb fluoro on mine with a mono leader on the other end of the swivel. I have never lacked any sensitivity or felt there was too much stretch in my line. But to answer your question, I don't know if the switch will help you as I find myself retying a lot with fluoro as my crig mainline. I think dragging any kind of line across rocks is gonna cause frays in your line. If you did switch to fluoro I would try either Sunline Shooter or Seaguar Abrazx. I use Sunline Sniper on mine and find I have to retie too often. Will be using Shooter when I re-spool.

I use power pro braid on a couple of different outfits, spinning and casting, and I have to say I don't think you can get any more sensitive than that. I find braid so sensitive that I can feel the contour of the bottom of a lake when I'm dragging. I use fluoro-clear by P-line instead of 100% fluoro, as it contains the advantages of both mono and fluoro such as its ability to sink/its invisibility in the water, but also better knot-strength than regular fluoro. I do think fluoro has a solid amount of sensitivity, but nothing compared to braid.

Braid is great if you have constant tension on the line. Any slack, loops, or bows and you're done. Current and wind can play a factor.

Yeah, bite detection on slack line is braids on downfall. You can keep tension in it, though, and the benefits outweigh that, I think.