I asked him what speed he was getting, he replied "around 3Mbps download, and 1.5-2Mbps upload" (using the TBB speed tester and over wWiFi). I gently suggested that was appalling, and not worth the fibre premium, assuming he was actually using fibre - though upload speeds suggest he was.
I suggested he rerun using ethernet to eliminate WiFi issues. He also rang Plusnet late this afternoon, got through almost immediately. The Plusnet rep. looked at his line (or whatever) and "changed a few settings", he was told to wait 20-30 minutes and see if things were better.
He's now getting, via ethernet, 35Mbps+ download, 1.8Mbps upload. Clearly much better. I've asked him to try WiFi speed test for comparison.
Assuming it was a Plusnet setting issues, any idea what that might have been?
Happily running Windows 10 on both desktop and laptop
We have more and more laws, and less and less enforcement