I wouldn't even call the G2 water resistant. The tailcap design is just not set up for water from the looks of it.
I think the G2Z is designed to be water resistant. You can get the NRA version of the G2Z for $75.
I think the 6P should also be water resistant. It is only about $50.
So, if cost is an issue I'd look at the 6P, if weight, the G2Z.
Al, you want to confirm or deny my guesses?
Thanks,
-john