in conclusion i would say line visibility matters at times.i would also say flouro is the least visible in ultra clear water.flouro becomes less visisible as light increases. it loses it's advantages as the water becomes stained.in stained water i feel red cast is just as good visibilty wise if not better imho.i find myself using less and less braid these days.i found seguar invizx to be a good flouro line but it still doesn't cast as good as red cast.being that i almost never fish ultra clear water i can't justify the cost in my mind of the flouro over red cast.others may like it for other reasons such as sensitivty and abrasion resistance.now we start decreasing my line diameters this year.instead of using 20 i will use 17 ,instead of 12 i'll use 10 etc...