We're quietly thinking about replacing our T5 Beach with a T6 Coast. I understand that the canvas on the T6 Cali is now made of "waterproof" polyester/cotton rather than just cotton. Has any T6 owner been out in heavy rain yet and tested the waterproofing without a topper? I realize that we'd have to close the "windows" during rain but the space-saving of not carrying our topper would be great.