I ride my Super8 in rain all the time. But, it's my only vehicle, so I don't really have a choice. I just put my 3/4 helmet on and my Frogg Troggs.
I haven't had an issue with the hard tires. I just slow down, and don't lean into turns as much.
Plus, riding the scooter in the rain, makes the Harley guys at the bar look like a bunch of panzies!
Duke-