I'm starting to think sensitivity is a little overrated and overused. I think back to the tackle I've used, 10 years ago, 20 years, 30 years, 40 years.....our rods and lines have advanced much over the years. We now have greater durability, lighter weight, and increased sensitivity in almost everything we use. For me, my high end rods are very sensitive and I'm skilled enough to see and detect most saltwater game fish strikes. The only time I place an extremely high premium on sensitivity is when I'm fishing for .......... crappie.
I love the FG knot. Strongest and thinnest knot that I've ever seen. It is also the smoothest knot for reeling/casting through the rod eyes. I can tie one pretty quickly too, but TBH, I'm getting tired of the hassle and expense. I've started to switch back to mono on a few baitcasters because I now think that a bit of stretch is good in some instances. Because of this, I'm starting to use mono more often for leaders with my braid. I'll probably stay with braid on the spinners because braid has less coil memory.
Back to fluoro for main line. I've not done it only because of expense and I don't feel that fluoro has a big advantage over mono in the upper Texas coastal areas that I fish. If I were fishing in Florida, then I 'may' lean towards using more fluoro. I do use fluoro for leaders on braid, but that is slowly changing to braid/mono or just mono.