UPDATE
I went to the place in Pui O in Lantau today off the back of this thread in order to check it out (wife's birthday in a few weeks, trying to shortlist options ourselves). Key message: DON'T BOTHER with this place, it is very disappointing in many ways.
After ordering some lunch, I asked the manageress whether they took party bookings and what they were able to do in terms of making arrangements. I got a grumpy blunt and unhelpful response along the lines "we don't open in the evenings, so we can't do it". After further questions about things I'd seen on the website e.g. Dinning on the beach, she said "yeah I suppose we could, it's $100 per person charge" - that was it! No, "definitely, we can provide this at the following charge" or "so sorry, we're unable to do evenings but how about something in the afternoon", just pretty blunt responses! Just in case it was purely me, my wife went to order sone drinks and she got the same "unique customer service". There are plenty more hilarious quotes, especially considering this is someone who is running a business so one would assume she'd at least try to make a positive impression, even if for this particular request she wouldn't be able to help. Anyway, I gave up when it was clear she wasn't interested in my future custom.
The beach itself is much wider than Shek O but not as clean/nice in my opinion, and from my limited contact with the staff at Zanzibar, i think the Shek o option is infinitely friendlier and more helpful!
One final thought, I wonder whether this place has recently been taken over by this new manageress as everything about the place is nothing like the website. Would be interested in anyone else's recent experiences of this place as I was genuinely shocked and surprised by the manageress' attitude.