Its a personal preference some like Fluoro and some like Mono. I like Mono myself as I only use around a 5 or 6 foot leader and usually fish no deeper then 180 feet so I think it works like a bit of shock absorber with braid.
I have also used Fluoro a bit as well bit I do prefer Mono.
I don't have any problems with it and it can't hurt using it even if mono gets just as many bites. Bait fishing another story, gotta use flouro. Fish like AJs, Tarpon, stripers, bottom critters I save the money and use mono.
I like 80 lb Braid, with a topshot of 80 lb Fluro. We could get 5-6 pgs over topshot lengths. Some people like it short while others "like myself" prefer a 50-60 ft topshot. Truth is, it's personal preference. When PB Tuna jigging i think that Braid is a must as the boat is not going to chase down your fish, should you be lucky enough to hook an eyeball. I always felt that the more line that you can spool the better
don't use suffix mono leader as I had a bad spool of it and lost the only fish I hooked into. Went to tie again and pulled on 80lb and it broke in my hand. "Must have been a bad batch" but I wont be using them anymore.