The only real sailworthiness advantage I know if is that if you're sailing with conditions big enough to make you surf (and downwind, i.e. not some weird situation where the wind and the waves are not coming from the same direction), being able to lift the keel helps avoid getting sideways and broaching from the wave trying to pick the boat "up and over the keel" in a sense. Granted, I've only personally verified this with many dinghies I've raced, but on a larger boat the dynamics might not be the same (I still don't have "big boat" money yet lol!).