Sorry for the late response.
Intel is very strict to publish any performance and benchmark data, it would be mis-guided and confused if we do it. So it would be helpful if you can be specific the performance you are interested, for example, hardware, OS, framework, content videos, expected performance, this way I can answer yes or no at least.
You can also refer to the published data in the following page:
Let me know if these help.
Yes, in general, the code should run faster on Linux than on Windows.
And you are right, MSS 2018 should run faster than 2017 in some cases for bug fixing and new features introduced.