I'm using current versions of Sonar, UAD, and Win10 (the later ain't exactly voluntary<G>!)...
I've run into two problems, neither is in any way new:
- the dreaded crash while removing a UAD Plug-in... hasn't happened in quite a while now, and when it did it was pretty rare, but you know, once bitten, so I am really careful, maybe a good thing, maybe I shouldn't have to be so careful?
- the dreaded plug-in won't load bug, rarer than it used to be, but still happens. Again there is a work-around, but it is annoying.
My system includes a PCIe Quad and an Apollo Twin USB.
In speaking with UA Tech Support I'm told this problem is a timing problem, and I don't remember the details (I'll try to dig up the email) but it has something to do with the say UA asks about resources and Sonar reports them. Their suspicion is that the same mechanism causes the crashes.
As far as support goes, it appears that the do test with Sonar, maybe on an as-needed basis, but they are familiar with Sonar. They don't, yet, support Sonar as an official platform, but I have been told, a couple of times, that it is in their roadmap. They don't say when, and it would be impolite to ask...
As a rule I upgrade UA the day I learn about the new version, always anxious to try new plugins! This did cause problems once, some time ago, but their releases have been among the most stable I use.
I also upgrade Sonar immediately these days, because the roll-back works so well there is no risk any more.
Other than that I usually wait for the second drop - I ignored this advice recently with NI Kontakt v5.6, and I really wish I'd have waited... oh well.
I was running Windows 7 up until sometime this summer - I upgraded to Windows 10 - on a spare drive - just to see what was what. I'm not blown away by Win10, but neither have I run into any show stoppers, so I never bothered to go back to Win7.
Last observation - ignoring the two bugs I mentioned the only risk to installing a newer version is that you might like one of the new plugins<G>!