Hi Martin
The PL 60mm F4 (240mm FL) with rings is a recent purchase and I have only managed to use it 4 or 5 times due to poor weather, lack of time, etc. and so far it appears to have worked well with the PL Guide Rings. It is a very light OTA.
The PL Guide Rings are bolted to a DIY aluminium plate, which is itself bolted to some Tube Rings, so it is a reasonably rigid connection.
The PL 60mm actually replaced a very old WO 66mm Petzval, which I think was 400mm FL but it was very heavy. I had this mounted in tube rings bolted to the Mewlon Tube Rings, so I have been pleasantly surprised with the PL 60mm F4 on the Mewlon thus far.
I have read that modern autoguiding algorithms allow a ratio of 1:10, but where possible, I like to keep below this, between 1:8 and 1:5.
I am a sporadic imager, so I don't have a lot of mount data to look back on, but from memory, the Tak EM200 was guiding at 0.3 to 0.4 RMS according to The Sky X Pro.
I set up and tear down each night and have just started using T-Point in The Sky X Pro. I run a 50 point model each time I set up. I use the QHY PoleMaster for PA.
The EM200 does not have PEC but I think T-Point and ProTrack in TSX Pro have probably helped with my auto guiding, they have certainly absolutely helped with pointing accuracy.
Cheers
Dennis
EDIT: Added photo showing PL 60mm and its Red Tube Rings.