We stayed at the St Regis to celebrate our 10 year wedding anniversary.
The room (517) was well above average against a standard high end hotel room, it had ocean glimpses, didn't exceed my expectations but overall was satisfactory for the price (circa 450USD/night++), spacious with a large free-standing bath, well decorated, a little tired but still lovely. My advice is to book at the St Regis, not because of the room, but because of the staff and the resort features - this place is absolutely worth your investment. If you are using the grounds to the full you will not be spending much time in your room anyway. What makes the resort the top pick in Nusa Dua in my opinion is firstly the breakfast (which is included for all guests in all rooms despite some deals on the web indicating otherwise), the breathtaking salt water and fresh water lagoons which seem to go on forever, with a swim-up bar and little nooks and features and shaded lazing areas everywhere to have privacy, including stone sofas in the middle of the pool, the lovely clean private swimming beach with chairs to laze on, a small man made "beach" and shallow sanded area for kids between the two lagoons, and the extensive grounds with gorgeous features and cabanas to laze on throughout. The resort seemed very low occupancy, bordering on empty, even though it was Chinese New Year - there is a lot of lagoon/resort space per guest. I only swam past one person the whole time I was there. Staff were pleasant and responsive to requests for the most part, and the feature to meet you at the airport to guide you through visa processing was very helpful in what would otherwise have been a very confusing process for even the most seasoned of travellers. The food was very high quality, in particular Kayputi. Highly recommended, especially the entree Wagyu Carparccio with fois gras and truffle foam. So good!
One very minor point on the Butler service - when I called our 'butler' to ask for menus for the restaurants in the resort, they put me through to the concierge who asked me to come down to the desk to read them. I said, isn't there a copy of the menus in my room somewhere? No, we have copies here, it's best if you come down. Only a minor point but manage your expectations RE what a butler service entails. The butler service is marketing speak for the normal service you would expect from general staff members at a 5 star resort - don't imagine 'Jeeves' will be there waiting outside your room when you call out for your smoking jacket and slippers. ;)
Another small point for management to note was the volcanic rock on the seat backs at the swim up bar seemed to leave a black oily film on your back that needed a lot of scrubbing to remove.
Otherwise the service was very satisfactory throughout our stay. We are looking forward to coming back for a longer visit next time.