I live in Siem Reap in Cambodia and I try to avoid the crossing from Poipet as it can be horrendous. Cambodian Immigration is usually easy BUT Thai Immigration in Aranyaphratet is dreadful. I had to queue for almost 4 hours at my last visit.
If travelling by car, I now use two convenient, easy and quick land border crossings in the north of Cambodia:-
O Smach, Samraong Municipality, Cambodia to Chong Chom, Surin Province, Thailand.
Choam, Anlong Veng District Cambodia to Chong Sa- Ngam, Sisaket Province, Thailand
Please note, at both of these crossings you have to complete a Form T6 to enter Thailand and an Arrival/Departure card to enter Cambodia.