Beautiful sites here. The boat from Sanur to the island is $40 a person which included the return back to Sanur. Approximately a 30 minute boat ride. The best way to book this fast boat would be to avoid the sales guys on the beach and head all the way down the boardwalk to the actual rental office. This way you will be assured that you will get there and for the correct price.
We booked 1 week here at the D’Nusa and were not happy with this hotel. The hotel manager would not give us an upgrade unless we paid an extra $170 a night. The hotel was pretty much vacant. Bus loads of Chinese would come every day to use the restaurant and the pool. We really only slept there and went down the beach every day to use other hotels.
Three nights on the island would have been plenty as there is not really that much to see and do. We spent our time mostly just walking the beach and having drinks and food at many of the restaurants along the beach.
The walks along the beach are beautiful and the sunsets are amazing.
The way to get around the island is to either walk or rent a motor bike, however both can be dangerous as there are no sidewalks and too many bikes, cars and people using the roads. We went around the island by bike with a local which only cost us $30. This was well worth it as he showed us a lot of sites which we would not have seen, had we not hired him. Also much safer as I rode on the back of his bike and Clint had his own.