Which one is more sensitive?

Braid has no stretch, thereby being more sensitive to feeling the bottom and fish. Fluorocarbon, despite the hype, stretches considerably more. That may not necessarily be a bad thing, as it's abrasion resistance and reduced underwater visibility are plus factors to consider. A better all around option is braid with a fluoro leader in my opinion.

Braid has no stretch, thereby being more sensitive to feeling the bottom and fish. Fluorocarbon, despite the hype, stretches considerably more. That may not necessarily be a bad thing, as it's abrasion resistance and reduced underwater visibility are plus factors to consider. A better all around option is braid with a fluoro leader in my opinion.

 

The best of both worlds!

Braid is the most sensitive, but there is some gray area.

 

In order to feel anything with any line you need to have at least some tension on it.  Fluoro remains 'sensitive' at lower tensions than braid...Which is important to many people (including me).  This is why you will hear the misleading term of 'slack-line sensitivity'.  Meaning that where you would lose feeling with braid, you could potentially still have it with flouro...Even if the quality of that 'feel' is less.  

 

Braid/flouro-leader is a very versatile option for sure (I use it frequently as well), but it can't replace everything that one or the other can do.  IMO anyways .

I've always used braid/fluoro leader, but this year I'm going to try straight fluoro for senko fishing.  I've always been happy with braid's sensitivity even on semi-slack line though.

Braid is the most sensitive, but there is some gray area.

In order to feel anything with any line you need to have at least some tension on it. Fluoro remains 'sensitive' at lower tensions than braid...Which is important to many people (including me). This is why you will hear the misleading term of 'slack-line sensitivity'. Meaning that where you would lose feeling with braid, you could potentially still have it with flouro...Even if the quality of that 'feel' is less.

Braid/flouro-leader is a very versatile option for sure (I use it frequently as well), but it can't replace everything that one or the other can do. IMO anyways .

This is pretty interesting to think about. However, in my opinion, the only time braid possibly could be less sensitive than fluoro is on a long cast in deep water. Due to the buoyancy of braid, the line would have a bow in the middle of it, but then again, fluoro will have a bow in the opposite direction due to its density. So I still say braid is more sensitive due to less stretch.