I went there last week, it is the best place to view HK because you are even 'higher' than IFC/Tai Ping Shan when you view outside. 雲海? the cloud is just above us so unless you live in the Riz Carton hotel above 100/F, otherwise, you are not able to be 'above' cloud.
All in all, there is only 'view' there and nothing special. No need to go if you need to pay $100 or more.
I went there in June and it was a clear day with very far vision!! very impressive. It was good that they have "buy 1 get 1 free" promotion on wednesdays for HKID card holders. I think if you go on cloudy/rainy days you can indeed see 雲海!! but what's the point of paying so much just to see clouds below you??