I'm not sure that Speedtest-cli is the best utility to run a real-world test, so I set my NewsReader on an internal WinBlows machine downloading a couple of large posts. Yes, some of us really do still use UseNet.
Here are a few graphs of the results. I think it's fairly obvious which is the run with IPS and without. The NewsReader showed an average download speed of around 50 - 55Mbps with IPS and over 100Mbps peaking at around 130Mbps without.
Cheers.