We stayed at the Royal Angkor Resort as part of a tour of Cambodia. The hotel is located slightly outside Siem Reap proper (about a 10 min tuk tuk ride), but very close to the Angkor Archeological Park. We stayed in the low season so the price was very good, but the hotel did feel empty and underutilised. The pool area is great, and the staff were friendly and very attentive (perhaps because there didn't appear to be many guests!).
The rooms are large and have everything you expect of a 4-5 star hotel, although the rooms did have a slightly musty 1980ish feel about them. Once again, perhaps the low number of guests might have contributed to the feeling of the place. The breakfast was not up to the standard of other 4-5 star hotels we have stayed in, including in Cambodia.
Overall, the hotel was nice enough, and was in an excellent hotel to explore Angkor Park etc. If the price is right, then it is a good value 4 star hotel.More