An interesting observation. At our condo our wifi is secured so I don't really need to use a VPN. A VPN will typically slow down one's connection speed, because of encryption, decryption and distance to the VPN server. Out of curiosity, just now, I checked my download speed, and it was 35 mbps -- perfectly usable, and I'm on Cox Cable.
Then I opened Hotspot Shield VPN (just playing around) and did the speed test again -- 58 mbps! Surprising, but quite nice. I ran the test again and got 52 mbps. So the server for Hotspot Shield (somewhere in the U.S.) was faster than Cox Cable's server.
I've noticed a slowdown in download speed at home (CableOne) and at our condo (Cox Cable) depending on when I'm on the internet -- faster in the mornings and slower in the afternoon when more people are on the internet and available bandwidth seems to be soaked up.
When on public wifi (RV parks, airports, restaurants) I always use a VPN to prevent snooping on my computer or iPad. Typically I don't use a VPN on our secured wifi networks, but from time to time I'll check a VPN (I have several) just to see what the connection speed is.
Now, no big moral to this story -- just an interesting observation.