I had a friend back in the day with four Bose 901's hung from ceiling, all four corners. Guy loved hard rock, metal played at extremely high volumes. Worst sound ever, all these other guys would love it, I'd be cringing.
The difference with hanging from ceiling vs any other isolation technique is you're essentially not coupling speakers or equipment to anything (other than fish line or whatever means you're using). The wire or whatever may send some amount of vibration to joists, but this minimal at best. The greatest defect I can see is, you may want to couple speakers to floor to assist in bass control.
When I hung my cd players and transports from ceiling you could see slightest movement from players. This elicited an airier, more spacious and relaxed sound quality from this equipment. All manner of coupling to platforms of various kinds could not reproduce these qualities. If I were running cd player or transport today, I'd continue with this.