I currently run it on a WIN7 computer, but am looking to upgrade my hardware soon.
Will there be major issues running Sonar X3 in Windows 10?
Thanks!

In general, it works fine.  There have been lots of threads about this in the past.
 
There's still the question of an O.S. update causing a problem in the future. Turn off the internet and you should be okay.  (The fact that X3 doesn't require online activation at least protects you from the CW situation).

X3 runs fine on all windows platforms from W7 up, probably Vista too. 
More of an issue for upgrades are from you audio interface or any hardware that requires drivers. Check company websites first to make sure your not left out in the cold. 
 
People keep repeating this myth that W10 will someday break Sonar. Not sure where they get this idea from. So far W10 has only caused issues, as I said, with drivers for hardware. People are using very old software on W10. On this laptop I am using Office 2003 without issue. I also run DVD shrink which is from 2004. 
 
If you keep system restore on you can always roll back your OS. 
If your buying a store bought PC or laptop it will come with W10. There are usually no options. 
But if you build your own or purchase from a custom builder you have the option of installing W7 or W 8.1 too. 
I has chosen W 8.1 as my "safe" OS. 

Go for it pdarg

Cactus Music
People keep repeating this myth that W10 will someday break Sonar. Not sure where they get this idea from. So far W10 has only caused issues, as I said, with drivers for hardware.

They get the idea from incidents like this:
 
https://steamcommunity.com/games/543510/announcements/detail/282995674662732546
 
I agree that system images are a viable safety net, but let's stop telling people Win 10 updates have never caused problems. 

My version of X3, though I do not use it as often, works great on Windows 10 and all of the updates. Admittedly, I have not used X3 for intense work that I do in Platinum.

JonD

Cactus Music
People keep repeating this myth that W10 will someday break Sonar. Not sure where they get this idea from. So far W10 has only caused issues, as I said, with drivers for hardware.

They get the idea from incidents like this:
 
https://steamcommunity.com/games/543510/announcements/detail/282995674662732546
 
I agree that system images are a viable safety net, but let's stop telling people Win 10 updates have never caused problems. 

i think a key point to the issue linked above is ....and it appears to only affect some systems since it is timing related. 

At at what point has W10 update ever stopped Sonar from running? 
I didn't say it doesn't cause problems, I am abandoning it because it does cause problems, but it has never actually trashed Sonar for me,, just my drivers and settings. 
So I agree to disagree. I don't like W10 but I still have it on 3 computers. 

I wouldn't rely on System Restore to reset Windows 10. I may be doing something wrong but even when I've set my own points all too often it fails to reset... and for no apparent reason I can tell. This was rarely an issue with Windows 7.

Thanks to all for their responses.
I guess I should also ask this:
I purchased the lifetime Sonar Platinum upgrade - but never installed it.
Is there any reason I should use Platinum if I am happy with X3? Any big advantages to using the newer version?
Thanks again.