Since my kickr Core can connect to two bluetooth devices, I have TR on my IPhone with my Assiomas as Powermeter and the Core through powermatch. Zwift runs on my IPad with the Core only as powermeter.
I enjoy the social aspect oft Zwift and the software- and trainingsplan quality of TR.
But I have to admit: best experience is a zwift workout with companion app or TR with tour de france relive and music…