These days, the Angkor complex is absolutely crawling with multi-national tourists. My advice if you are interested in going and taking photos is plan to do the opposite of what everyone else is doing. At the crack of dawn, everyone will be trying to get a pic of the sun rising behind Angkor Wat either from the nearby hill or smack dab in front of it.
(this is a stitched panorama comprised of 15 raw files)
Motor on to Bantey Srei even Bayon. If that doesn't work plan a trip to Beng Melea.
Depending on how border tensions are going, I highly recommend visiting Preah Vihear form the Khmer side.