I haven't had any issues so far but it's been less than a week and I haven't tackled any large projects yet. My system is running an Apollo UAD Quad with a handful of Waves plugins, UAD, a bunch of Arturia stuff, Soundtoys, etc.
What aggravates me the most is that I can't run some of the older stuff like Ethno 2 and MOTU wasn't helpful at all when I asked them to give me a couple more iLok authorizations to try and get their MOTU instruments and Ethno running again. Dealing with iLok's BS is one of the worst things about having to upgrade. There's always a catch with iLok.... and it always happens when you under a ton of stress. It often seems as if they want to punish you for paying for software..... seriously.... There has to be a better way!
One nice thing was Soundtoys. Their customer service was excellent!!! I contacted them with my iLOK issues and they immediately fixed my authorizations, unlike MOTU who passed the buck back to iLok.
it took me days to download the software and make it play nice again, partly because my Wi Fi decided to act up after my iMac died. I spent a lot of $$ on adapters alone just to get my ethernet and thunderbolt stuff going again..... Oy Vey....
I don't know about Apple anymore.... Their products do not seem like they are built to last in my humble experience. I say this reluctantly as I have been using Mac's since 1985. I started on a Mac + using Opcode's Vision....
What a long strange trip it's been.....