We have stayed at this hotel several times over the last 8 years and have seen improvements both in service and cuisine ( menu books could do with an update ). Rooms are clean and tidy with Wi-Fi, TV, and air conditioning.
Hotel is central with markets, banks, and a variety of shops close by. The Tuk-Tuk drivers are reliable and a taxi is available over the road which is considerably cheaper than the hotel booking one for you.
Personally we use the same driver of a mini bus from O BaK Om for our and the family transport as he will take us to destinations that some other drivers will not and his pricing is fair.

It is nice hotel with comfortable room and friendly staff

I recommend the Asia Hotel. Fine rooms, not-so-nice bathrooms. A bit overpriced but everything else was okay

I stayed here two times. I chose Asia hotel over riverside are because we had business in downtown. Its smooth five minutes drive to riverside anyway so its not a problem. Hotel is located next to a busy street but you don't get much of noise in to your room. But if you are a light sleeper, ask room NOT facing Monivong street to be really sure to get sleep.
Summer time hotel was still having problems with smelly bathrooms but last visit in November we had no problem.
Everything in the hotel is worn and rustic. Rooms are basic. A bed, chair, table and fridge. Awful hard towels. Aircon is on-off model. But this is what you can expect when room price is around 20$. We paid 25$ for slighly bigger room.
Plenty of tuk tuks waiting in front of the hotel. Don't let them scam you! One way to riverside is maximum 1,5$.
No restaurants nearby. But only a 2 minute walk to center market. Skip breakfast (which is not good) and walk to the market for fried rice.