I travelled on the new Yellow Line on the first day of operation, from Hua Mak to Samrong and back.
I was expecting it to be super-crowded, but it wasn't - plenty of people, but not too busy.
I know that this is a secondary route and cost was an important factor, but while the trains are fine, the ride is quite bumpy - uncomfortably so at some points. I imagine that this will only deteriorate as the line ages.