Looks like it could be good value (at opening rates at least), but I'd have to be convinced about the isolated location. It is geographically close to DL, but I'm not sure how easy it would be to get there. It says there is a public bus to Sunny Bay (about 8km) and Tung Chung stations, but I don't see any bus stops on google maps (unless it's a new service specifically for this hotel) and I wouldn't know how frequent/reliable the HK bus service is either. Not sure how else you would get around without your own transport. It is a nice trip on the ferry between Central and Lantau, but not sure I'd want to do it too many times, and the dock seems to be a decent walk from the hotel.
If I had more time in HK on my upcoming trip, I'd be happy to check out the transport situation for you (I think it could be worth further investigation), but I don't think I'll be able to fit it in.
Personally I think the trains are so awesome in HK, I wouldn't really consider staying anywhere that wasn't within walking distance of a station.