When I first tried W10 about a year ago I found that by the time I'd killed off the flagship MS applications that I had no interest in (Edge, OneDrive, Cortana) I was pretty much left with W7, but with a less pleasant/familiar interface. So what was the point? (I rolled back.)
More recently I wondered about the speed thing, so I cleaned up a W7 laptop we have, but don't use much, by removing all the games and similar software, used CCleaner, made sure it was defragged and then ran a test boot from cold to time until it was (really) ready to use - ie. when all the services and stuff have started and not that half life situation where you can 'use' it, but it's a dog. Result: 2 mins 40 secs.
Then I let W10 install, ran through all the reboots, updates, etc till it was a steady install. Reran the cold boot test: 2 mins 30 secs.
Faster - yes. Worth the bother - no.