Always had a bike, not always had a car, so not that bothered about rain - as the old saying goes "there's no such thing as bad weather, just bad clothing'.
I tend to leave my hood off for about 8 months of the year, and then put it on and leave it on from Nov to Feb. I keep mine outside all year, and the cover copes with the weather better with the hood on.
I have the Librands screen steadies which alleviate the problems with the side screen bowing out. I also have a couple of strips of rubber window seal that I put on the side of windscreen to make a good seal when the tops are on.
However, I don't gain any pleasure in getting wet, which is why I have the BGT. If there's a 75 -100% chance of rain I'll the the GT, if not, the Mog.
As much as I appreciate the technology and performance of Porsche, I have absolutely zero interest in owning anything bar a 356.