Why do the G19/G23/G32 all use a stock 18# recoil spring? It this just to provide reliable function with really weak .40/.357 ammo? It's time for a new spring in my G23, I was going to get a 20#. Do you G32 owners prefer 20# or 22#? I think I might get a .357 barrel also. How is the G32 magazine different? Thanks.