In any automatic, there is always a balance of necessary spring strenght. A perfectly balanced spring will "barely" allow the slide to bottom out against the rear stops and then push the slide back into battery without excess energy. If it is too strong, the slide won't rack all the way and you'll get jams. If it is too weak, the recoil will force the slide back too hard and put unnecessary wear on the slide stops. I may also not be strong enough to force the slide back into battery.
Manufacturer's put an "average" slide on to handle a wide variety of loads. If you are routinely shooting very weak target loads, then you might benefit from switching to a weaker spring - one that wouldn't overpower the recoil provided by the weaker target load. On the other hand, if you are shooting hot loads, then you would probably benefit from an extra power spring that would absorb more of the recoil before the slide bottomed against the stops.
I know that Makarov shooters will routinely switch to a stronger spring. The factory springs were originally designed for Russian rounds that aren't quite as hot as the factory rounds available today. Going to a spring with just one or two pounds of extra strength helps smooth out some of the recoil snap without interfering with feeding.