Springs have a significant influence on feel and playability.
When does one replace the springs? Depends on the individual. An enthusiast who puts 6 hours per week into moderate playing, may end up replacing the entire pedal before the springs are worn. But a working deathmetal drummer, playing, practicing, and/or rehearsing 30 hours per week, who has a heavy foot and likes tight springs, may find the springs need to be replaced every 6 months.
It's your call. If the springs feel sloppy and you've tightened them as much as they can go...replace them.
