I read above about a few guys using Fireline. I have been using it for about 5 years now, 6-12lb on my Spinning rods and 50lb on my Catfish rod. On my spinning rod I use a mono backing then spool rest with Fireline. On my Catfish rod however, I use all braid. A few years back I hooked into a pretty big fish down on the river and it ran my line down to where I used to split braid/mono and it instantly broke off and the fish was gone. If you are targeting big game fish I would highly recommend using all braid on the spool.