I just finished a flight in VR to try out the cloud shadows enabled.  After finishing the flight I'm disappointed. The shadows look so good, they massively improve the immersiveness, I was just floored with how much depth it adds to everything just having those there.  I also found that the way the shadows gradually darken the cockpit is great as well (I don't get why people complain about it, it's exactly what's supposed to happen, just need to turn on instrument lighting and you're set).