I decided to pick Shadow Angkor Residence based on a combination of location (5 minute walk to Pub Street), price and customer feedback. I booked on Expedia about 24 hour prior to stay, and received a follow-up email shortly after I booked.
I then corresponded via email and quickly arranged to be picked up by the hotel's contracted tuk-tuk driver at the Siem Reap airport. While processing my early check-in, they asked me to be seated and provided a nice cold ice water and a scented moistened toil.
I explained to the hotel in a prior email and also when I arrived that I was interested in touring Angkor Wat and other recommended sites a friend had passed along. They explained the options for Angkor Wat and beyond for Day 1 (and the 5:00 AM sunrise) and the "Grand Tour" for Day 2 and had the tuk-tuk driver arranged for me, as well as getting the Angkor Wat World pass before ticket office closing (and if it weren't for the weather, I would have also seen Angkor Wat at sunset).
The room itself was as pictured in Expedia, along with fresh towels on the bed decorated beautifully with flowers and the room with a scented tea light candles.
The complimentary breakfasts I had were the mango pancakes with fresh fruit, which was excellent.
Internet speed was good and worked fine, as did the cable TV (CNN, CNBC, etc.)
The staff was really helpful and friendly.
Overall, I really enjoyed by stay at Shadow Angkor Residence, especially since all of my plans were all very last minute.