Train from oruro to Tupiza/Villazon?

Hi,

Im looking catching the train from Oruro/Uyuni/Tupiza/Villazon(bus?) then onward to Argentina early in the new year. Has anyone done this trip? How did you find it? What is the standard like on the trains - Wara Wara del Sur and the' Expreso del Sur. Does anyone know if the trains still run to the border at Villazon?There is a message on the website saying that the service to Villazon is suspended but all the timetables still mention Villazon. Any help much appreciated.