Actually I spoke too soon earlier. This really isn't great. The Pro Tools GUI has slowed down, it's like the old days when you were using a lower buffer size with a high track count, it takes about five seconds to stop after you hit the space bar and the display lags behind playback.
There's already the issue with Synchron series instruments where they take a few seconds to open or switch (see: https://forum.vsl.co.at/topic/59824/gui-slower-response/22). It's possible to work, audio is OK, but it's pretty frustrating with two sets of delays involved. I don't know whether this is only with Pro Tools. I've not noticed it with anything else so far, but then I've not used any other software intensively. I hope this gets sorted out. I deliberately held off on upgrading to Sonoma until it was qualified for Pro Tools, VSL and a couple of other manufacturers whose stuff I use a lot.
Oh well. I'll see if I can find out any more but anyone else thinking of moving to Sonoma might want to check whether there are issues with their DAW or other software.