If the 60% rule applies to 80# Whiplash, then it would have the diameter of 48# mono. A braid with diameter similar to 17# mono would be around 28-30# braid. My best luck overall has been with 20# Fireline on spinning reels (SS4400 & 4500, Sustain 4000); Riptide 12# on Prion 1800; 45# Magibraid on conv. But that's me.
I use uni knots all around, and uni-to-uni to join any two lines together, whether it's mono to braid, braid to braid, or mono to mono.