I have stayed at the Cara Hotel a number of times and found it to be the best hotel for the money in much of Asia. Anyone coming to Cambodia on business or pleasure I also book at the Cara and everyone has been happy staying there.
The staff are the best I have experienced outside of a 5 star hotel, the hotel is very safe, the tuk tuk drivers are all regulars and helpful and honest, the rooms are clean with great beds and the best pillows. Everything works which is unusual for anything but high end hotels in Asia. The hotel restaurant has very good Japanese/Korean food at a reasonable price and a decent free breakfast.
The negatives would be it is not centrally located which means a $2 USD tuk tuk ride to the river side area and the rooms can be a bit noisy at times if you get an outside room with a balcony which I always recommend.
Most rooms have wireless internet and the business center has free internet PC's available. Cambodian high speed leaves alot to be desired but that isn't the hotels fault.
The Cara is far better than other hotels in Phnom Penh that cost twice the price.

I have been there last year and find it surprisingly beautiful. With that kind of setting, I guess it is worth more than the prices we paid for the 3 night stay. Expecially the foods, they are gorgeous. I expecially like the chicken rice pretty much and still miss those fusion starters that I ate. The hotel has also shown enough care to those people with small kids. Since I was taking my 3 years old boy along with us and was pretty much concerned on the water quality in Phnom Penh, to my surprise they offer "Evian" spring water, that really relieved my worry. Everytime we had our meals there, the first thing first, the staff will definitely ask if we want evian water. So 1 thumb up for them in this particular area. Love it.

We stayed at Cara after the original hotel (Blue Lime) we booked told us they were booked out and Cara was the only other hotel we could find for USD40. The girls at reception were unofficious and unwelcoming. We opted for the cheaper room option given we were only there for one night en route to Siem Reap (and lucky we only stayed for one night!). The room had no windows so the room was dark and dinghy with air con which didnt work properly. The safe didnt seem very safe and didnt work anyway. When I told the girls at reception the safe didnt work, she just looked at me and shrugged. Then when I suggested I deposit my valuables with reception she baulked and told me that she was due to go home soon. The internet facilities were extremely slow and there were mozzies all over the hotel. I dont know what the other rooms in the hotel are like, but the room we stayed in was definitely not worth USD40 (it was hardly worth $10), dont be fooled by the foyer and spa which seem sort of fancy cos the rooms certainly arent! Prices for the spa were ridiculously expensive for a 3rd world country. Also, the hotel wasnt very close to anything of interest. Definitely do not stay in the room with no windows! We will not be coming back!!

We stayed at the Cara during our Intrepid Tour of South-East Asia.Hotel was ok,room was a bit small and therefor furniture was all crammed in.Our room had a balcony but there was no chairs to sit on,anyway no view to speak of! Nice business centre and entrance to hotel.Breakfasts was good.Location was a problem-we always had to take a moto and could not walk anywhere because of the distances involved.Not a bad hotel,but would not stay there again.