I live in Ma On Shan, and have visited 西沙 cafe for few times over the years. I was DISAPPOINTED every time. I didn't want to go a second time, just different friends dragged me there for a try-try.
The foods were bad. They priced as if they were a 4-5 star hotel, but gave you product quality worsen then many local fast food stalls.
There are a few restaurant/cafe along the 西沙 road, but the quality is so-so. There was a good one inside White Head Golf Driving Course but sadly it has been closed.
If you want to eat differently, try the one right next to the Ma On Shan Public Swimming Pool. It's name is SA Pool Side Cafe for something like this. The price and quality are both around a 3-star hotel, but it has glass walls by the pools so it has a style.
I like the pizza there, I think it is better (and cheaper) than Pizza Hut. My 9-year old daughter loves the minced beef spaghetti, she sees it is even better than 5-star hotel's.
There are a few restaurant/cafe along the 西沙 road, but the quality is so-so. There was a good one inside White Head Golf Driving Course but sadly it has been closed.