Way before Covid... I did BKK to Chiang Mai... Overnight sleeping berth... ac car... squat hole in the floor for a toilet... prepackaged bkfasts in the kitchen car...
The thing is, they have to change the rail gauges somewhere along the way... and what was supposed to be simple, took hours... (aka sun up, before we were on our way again)... Banging all night while they were making repairs... Impossible to sleep...
Will say, glad to have experienced Thai railways at their peak efficiency... ;P... Never again... Flew back to BKK...
... cant wait for their engineless Chinese highspeed trains... Probably be waiting forever...