I have no significant technical complaints after four years of heavy use. My core is a Roon Nucleus. I have to reboot my core maybe twice a year. Loading up new zones is slower for me now when I open the app, which is a slight annoyance, but I do have a lot of zones.
The one time I had a serious problem, I received good direct support after posting my data in the Roon forum.
Overall it's a great product and I frequently marvel at the fact I can have such great technology at my fingertips.