I have been using it (20# Test) for a lot of years, and have at least 30 rods spooled with it (for trolling on Erie)!
I either use it for backing for my leaded line reels (we fish down to 120'), and as main line on reels with out lead. Some I'm running has to be over 15 years old, and never have I had the Fireline break.
I usually run 50' of 20# Seaguar Fluorocarbon as a leader between the lure and the Fireline.
19 more in the boat !!
When the Fireline Crystal first came out, I had trouble with the lighter poundages breaking on my perch rods. I changed them out to regular Fireline, but I think they may have gotten the problem fixed with the lighter test breaking. At least I haven't seen anyone complaining about it anymore...
A lot of the braided lines actually break at a MUCH higher point than advertised.
Here's a list for 20# test lines...
20-POUND BRAIDED-LINE TENSILE STRENGTHS
Manufacturer Line Color Actual Break (Lbs.) % Rated Strength Variance
Berkley Fireline black & flo-green 54.5 273% H
Triple FishBully Braid Moss green 46.3 232% L
Cortland Master Braid Emerald green 41.6 208% L
Cortland Spectron white 41.3 207% L
SpiderWire Stealth green 39.7 199% L
Stren Super Braid hi-vis gold 37.6 188% L
SpiderWire Spiderline Moss green 35.7 179% L
Ande Braidfluoresc yellow 34.6 173% L
Western Filament Tuf Line black & white 34.5 173% L
Western Filament Tuf Line XP green 33.8 169% L
PowerPro Superline Moss green 33.0 165% L
Platypus Bionic Braid pink 31.5 158% L
Izorline Spectra green 30.5 153% L
Offshore Angler Magibraid green 30.0 150% M
Cabela's Ripcord Si Plus green 27.6 138% L
Sufix Performance Braid lo-vis green 23.4 117% L
Standard deviation: 0-3 = L (low), 3+-6 = M (moderate), 6+ = H (high)
Bill