tu-144
VH-KMH
You posted "Has there been any problems or controversy with it?"
What apart from:
1. the whole idea was stolen from the UK/French as an espionage exercise by the Russian KGB to obtain new technology
2. that the prototype crashed at the Paris air show under murky circumstances
3. that they had to fit the thing with retractable fore-planes to make it fly properly, which filled up the front of the passenger cabin with the operating mechanism.
I do believe it did carry some fare paying passengers but not many. The normal Russian procedure was for the aircraft to go into freight service first for a period of time before passengers were carried.
Was it is most of the aircraft have long been grounded, apart from 1 that NASA gave the Russian's enough money to refurbish it for some test flights. I think even that has stopped now.