To be fair it does make a few stops, like the food court in Korat for maybe a half-hour, a fuel stop, maybe some dallying at the terminal in Udon Thani, etc. Also between UT and NK the buses will be flagged down by Immigration Officers looking for Lao people to shake down.
The bus to Nong Khai will drop you off a block away from the Thai exit post. Usually. One night it dropped me off at a terminal on the other side of town.