Good experience. First time using the service, was a bit confused at the bus station, but staff helped out.
The bus left on time. Seats assigned when you exchange your voucher for ticket at a designated counter at the departure station.
The bus made two stops for leg stretch and bathroom breaks. Border crossing pretty straightforward. Drivers were helpful and spoke some English to answer my questions (much appreciated, as I do not speak Thai). Bus arrived to destination with about 20 min delay, but that was due to some traffic. Would use this company again.