Those visiting now and in the next month or so are in for a treat because you get the best weather (only hot to very hot), reasonable humidity, no rain and SMALL CROWDS!
The huge resorts in Siem Reap are nearly empty. The glut of large tour groups from China in the last few years came to an abrupt end. We had to wait in line for a few minutes for the steep climb up to the third level of the temple but according to our guide it is normally an hour or more in January.
The higher levels of the temple were recently closed to tourists because some jackass tried to take a souvenir :(
While the scale is not as epic as I imaged, it is nonetheless very grand. The temple was never completed and some rooms are still in the rough. The quality of carvings varies wildly.
If you are self-touring, HIRE A GUIDE!!! Better yet hire a private tour for a day or two as we did. Angkor Wat is just one thing to see in a FAR larger area. You will appreciate the guide's knowledge of the history just as you will appreciate their knowledge of the layout, best time of day and approaches for photographs and your driver waiting near an opposite exit (when possible) with small, cold, wet, eucalyptus infused towels to place over your face.