I was a Garrard 401 owner for many years, it was mounted in a 9 Stone in weight Granite Plinth.
The Garrard had undergone a Platter Bearing upgrade, so was not entirely original spec'.
I moved onto a PTP Solid Nine with the PTP Bearing and a Speed Controller.
I have not compared these Two TT's side by side, but feel sure the PTP is a very good version of a Idler Drive TT.
Additionally, not too many months ago, I have been demonstrated a newly owned 401 which is mounted in a compressed Bamboo Plinth.
The demonstration was carried out in a system, that I had used the PTP in, with a short period of time between the two sessions.
I do not recall any differences that would suggest one is noticeably differing from the other.
I am not aware of any location a review can be found, comparing the PTP / 301, where TT's have been identically mounted, with the same Tonearm>Cart' and system in use.