I suppose it is crossing the border and the trip in it's self. I have traveled from Bangkok to Siem Reap and back many times in past years, the old rattling bus from one of the bus stations in each city, cheap bus travel, but change at the boarder. I would stay overnight on the Thai side, near the market area are a few good hotels/guest houses, and still some good Thai food around. In the morning tuk tuk to the boarder then free bus has I remember to the bus station, shared taxi to Siem Reap.
If I did that same journey from Patt I would drive up in a rental car, leaving the car at the good guest house on the Thai side for a few days, time to look at Angkor.