Just upgraded to Win8 on my main DAW, more out of curiosity and the low cost than anything else. When working in Sonar, there's not that much difference to me. I don't have a touch screen. I find Windows 8 to need a few more mouse clicks to get things done, but on the other hand it have quite a few cool new funcions and work flow (navigation flow?) enhancements from Windows 7, which makes me happy about my desicion to upgrade. Sonar seem as stable as ever. I am extremely happy with my current set up.