I've had good experiences sending and receiving goods from Phnom Penh. The big bus takes a while getting to Phnom Penh, but other than that, I really appreciate this place. It's helpful to speak Khmer or have a person who can translate for you, though if you speak English you'll probably be fine (just realize they might not understand if you have a specific need). Friendly person at counter.
Was dropped off here on my way to Laos after a long trip from Siem Reap. Was told to wait here one hour for another bus. 4 men were in the area getting drunk and being loud. Not a nice place