I don't bother with much with flouro any longer. The visibility issue is overstated. There is an interesting mathematical analysis here http://www.bigindianabass.com/files/fluoro_present.ppt and a great discussion including modeling here http://www.danblanton.com/viewarchiv...arch201203.php.

Here is a video that shows supposedly invisible flouro in action. That little pulse of light that travels down the flouro tippet is kind of cool.

http://vimeo.com/39597433

I can see both mono and flouro in the water and so can the fish

I never had an issue with flouro sinking dry flies with light tippets. I had more of an issue with flouro tippet being less supple than mono leading to drag issues.

Abrasion resistance is more a factor of the formulation of the line and diameter rather than it being nylon or flouro. Nylon can be harder or softer than flouro. In the past, for nylon and flouro of equal breaking strength, the flouro would be thicker , which would provide greater abrasion resistance. fFlouro has improved in that respect over the last few years.

The June edition of California Fly Fisher has an excellent article by Ralph Cutter on nylon and flouro monofilament where he points out real world observations and experience with both types and shows that many of the claims about flouro compared to nylon do not hold up. . The article also includes comments from some very good trout anglers, some of whom prefer nylon and some prefer flouro.

In my own experience fishing for trout, bass, panfish, stripers in CA, and saltwater, whether fishing with a guide or on my own, I have never experienced any advantage of flouro over nylon. Any differences when they occurred were explained by other parameters.

Yet I have heard many stories where anglers experienced improved success when switching from one to the other

I started by saying I don't bother much with flouro. Which is not the same saying I never use it. I still carry some and occasionally tie some on to see if it might make a difference when things are not going well. Just in case