I hold on to rods for a long,,, long time. I only discard rods if they have broken in some way and they are upgraded.
If you enjoy your current lot of rods then stick with them, I say that, because if you get your hands on current rods, it will cost you a chunk of $$ to replace your current lot. The materials going into today's rods are unbelievable. How rod manufacturers have been able to produce light, strong rods, is impressive. Once you get your hands on these newer blanks and fish with them for a bit, you will be ruined!!