After having Kumho Ecsta LX I got brand new when I bought VW CC as CPO, I do not want to see Kumho tires on youtube as advertisement let alone having them on a car. That is how bad they were in wet. Hydroplaning? They were excellent! But braking and holding road? IDK< I think if I opened door and put my foot out to help slow down vehicle, it would work better.I've hydroplaned before (when there were puddles due to road condition) and have seen the result of pileups on wet roads. It's clear that stopping and steering are poorer when the road is wet. It's not quite as dramatic as ice or snow. I've never lost control in wet weather because I would slow down.
However, the worst thing for me when it's raining hard is visibility.