I find the pitch shifters track best with all the formant and smooth chords options turned off. Not sure if transpose has those or not.
All pitch shifting is a little robotic - it has to time shift lots of samples then put them back together. It has to detect pitch to know how to phase shift them so the resulting waveform isnt full of jumps. Its never perfect.
That said my last experience with transpose was very positive. It was very transparent
It used to sound great but now it doesn't. It sounds like garbage. I have tried smooth chords on and off and that still doesn't help.