I selected Mariya Heng because of positive reviews by others.  I made a multi-day guide arrangement with Mariya.  She assigned me guide Bunthoeun, who did an acceptable  job for the first day.  But in the afternoon he mentioned he would not be available for the next day as he had a prior commitment so I contacted Mariya and she was surprised by this.  She said she would arrange another guide for the next day.  I invited the next day's guide to join us for dinner (through Mariya) where Bunthoeun was taking us but she did not attend.  The next morning no guide shows up.  I call Mariya.  The second day guide had been cancelled.  This was really poor service.  It seems Mariya might be a better guide than she is a business manager because she did a poor job managing her guides  with me.  Although all her communications prior to my arrival were good, she did not do a good job when it came to the actual guiding.  

I ended up going out on the street and arranging with a tuktuk driver named Ni.  He actually did a greart job.  And a lot less expensive for the day than Mariya's service.