> > I still just disconnect everything when I am not using the station.
This is probably the single most effective method for protecting your
amateur equipment. Even the SPG cannot be counted on entirely
protecting your stuff from nasties. And one does not need to take a
full hit to receive damage. Close-by hits generate all kinds of
transients that take out stuff like phones, modems and trasceiver filter
switching diodes all the time.
I practice good hygiene and usually have the PL-259s (and all the AC,
phone lines, LAN cables) disconnected at my station. However, the
antenna/rotator/etc. wires still pass through something (a window or a
wall) and enter the house. It is at that point one has allowed
"lightning" (or its effects) to enter and somehow at or near that point
it should be dealt with - enter the SPG.