We used Synon during our stay in Siem Reap and he was wonderful! We booked him for 2 days and he drove us to some temples we hadn't had a chance to see on our tour. The 2nd day we decided we just wanted a drive to the airport in the late afternoon, so Synon (who had booked an actual tour after we said we didn't want to do more temples) got his younger brother to drive us and only charged us $10. (we had told Synon we'd still pay the $35 for a full day, even just for the airport trip, but had no issues with his brother driving us so Synon could take a "real" tour....)