Callum, trick to do is to look through this
TU154 accident list, eliminate hull losses due to environment (weather related, terrorism, accidental shoot downs, etc) or pilot error and see what you have left that can be levelled against the aircraft itself. Then do the same for any western type designed at the same time (you will not go far wrong I suspect with the B727) and see what you have. It is a crude methodology and yet hopefully allows an objective view of the TU154 safety record. Point is, the TU154 was designed for crude USSR airfields and must be an incredibly tough design even if, as The Steed describes, the interiors are, shall we say, less than inspiring.
Recent PPRuNe discussion
here.
The Steed, have also experienced the 'steam' effect you describe, most memorably while boarding a Sibir TU154 (I believe the actual aircraft destroyed by a suicide bomber a month later
) at DME one hot humid Moscow summers day. Air con was obviously working overtime and stepping into the cabin from the steps was like walking into a wall of fog. It was impressive how each vent was kicking out a little cloud. Presumably the humidity control on the air con is crude or hard to adjust.