A valid point. However, I think we tend to hear about the leaking ones more than we do about the ones that are ok. A good friend has a four month old Cali and been out in all this weather. No leak. He isn't a forum member and wasn't even aware that there was a potential issue. I get water ingress through the top of the tailgate of my current van if it is chucking it down and the pop top is up! We tend to use a roof topper anyway for privacy and sound insulation.
I did a risk analysis. In my case it works out financially. If i did keep my existing van, which is valid advice, and damaged the bellows then i would have to replace them with the new ones.
Most probably the main reason for taking a risk on the leaking bellows:
Having seen the sports pack on an Ascot Grey I regretted not going for it. It looks stunning. Haven't made that mistake this time around.