I disagree with the above on the overall balance of Bali vs Java. If you are flying from the USA on Day 0 and arriving in Bali on Day 1, you shouldn't consider leaving Bali for Java before a full week is up (i.e. on Day 8). There's LOTS to do and see on Bali and I don't mean sitting on the beach....though of course that's available if you want. There's nothing on Java on this list that warrants shortchanging Bali, IMO. That includes Borobudur and I say that as a "temple freak" and professional architect. And Java culture isn't remotely as interesting as that of Bali.