Mr Red wrote: the only possible actual advantage [of Win 10] they put forward was the inability to switch off updates. Which is not an advantage IMNSHO

I suppose ideally an operating system should enforce updates on everyone else, but not me ;)

There are quite a lot of extra security features in Windows 10. (Google for KASR, VBS, or HVCI for example for the gory details.) Mind you, some of the most effective need a modern PC and won't apply to machines sold with Win 7 which have been updated. Others require Win 10 enterprise, which won't come 'free' with a PC.

Last year's Wannacry ransomware affected Win 7 machines mainly.