My own feeling is this.
I make a backup image of the system - it takes about 15-20 minutes.
Try some new stuff.
If it works - keep it. If not, restore old image. That takes about 20 minutes.
So it only takes about an hour to try something risky.
I am not usually of the mind 'that if it ain't broke...' because you never know when something will break due to all the constant updates we get.
I am a hobbyist, so this is just fun for me, it's not a business.
Anyway, I used an older project that I made to test system performance.
The project has 20 tracks, each running a very CPU intensive performance in Maschine 2. Each track is running a different performance and each one uses a lot of effects on the sounds.
The output is nonsensical, because the performances are random, but I can tell if there are dropouts, etc.
The following shows the latest results with the new Focusrite drivers, Sonar Everest, and all the latest 'soon-to-be-Win 10' stuff. I have Kaspersky 2015 running and all the networking stuff. If I had to, I could disable a lot of services and features, but I don't have to do that.
You can see the 8 cores are all reasonably well distributed. The CPU is running at 4.3 gHz on most cores and the temperature is 70C - about as high as I ever see it. Latency is fine.
I let this run for a while and then load LatencyMon and grab this picture:
(You can right-click, load in new tab to see it full-sized)
It's not any slower than in the past, that's for sure. Maybe a bit faster.
I should throw in a few instances of Kaleidoscope to stress it some more.
During all this, mouse and Windowing performance is fine with no sluggishness.