Working with Mac Studio here too but with Mac OS Ventura beta and PM6 build 6552 is seriously slow.
I need to wait couple seconds for it jump to the next picture when going through R5 cRAW files.
You might have more issues coming your way when Mac OS Ventura goes out in few weeks and most people will have very very slow PMs.
Hope you can resolve it soon.
I am fairly confident that whatever the issue, it is unrelated to the one-time translation of the program through Rosetta, and there is likely a resolution that can be found for you in the current iteration of Photo Mechanic 6/Plus. We have several Apple Silicon devices in use at Camera Bits (all of which are less powerful than your Mac Studio, including my M1 Macbook Pro which is where we are currently testing Ventura), and none are able to replicate the speed issue as it has been described. Most customers, like Kevin, report great performance with Photo Mechanic on these computers, and like our Lead Developer Kirk said above, much of Photo Mechanic is IO bound, not CPU bound, and these computers have very fast SSDs.
I invite you to open a ticket with our Tech Support team by emailing support@camerabits.com or calling our office at 503-547-2888. We can do a screensharing session so you can give me a real time demo of this issue and I can provide whatever suggestions I can think of at that time.