P-Line 100% Floro is what I use and it generally lasts a season and if not it is because I lost too much on breakoffs. Experimented once with some 8lb on a spinning rod and it lasted 2 years no problem? The 3rd year you could tell it was just done. All my line is stored in my basement out of the light and I have bulk spools that are still good after 8 years. As far as the line breaking for Floro it is bad coming off the spool or it takes years of use. My worst experience was with Berkley Vanish, I couldn't even tie a knot without it breaking.
Allen