one problem with ground probes is they flow current when induced voltages exist in the tank.
also, you have to know that if you have a ground probe you MUST have GFI's to eliminate a potentially deadly scenario.
arc fault and gfi will not stop an electrocution via lighting since the fault would be transformer isolated and not grounded.
SO. I won't ever use a ground probe with my GFI's on in-tank equipment, and there is no use for a gfi on lighting circuits.
But, one thing that makes me happy is the fact that a tradesman calls the things GFI's vs GFCI. I still say GFCI is redundant and incorrect. a ground fault IS a ground circuit. so, to me, saying <I>ground "circuit" circuit interrupter</I> is silly. but it seems like common usage has overridden, the inherant ignorance of it.