Thanks. I seem to be in a hard place now with my other half. She seems insistent that the Nest bizarrely either needs to be wired via old thermostat wires, or via usb. Now she's freaking out that because I want it on the wall in the hall; our gasman or electrician has more work to do - or can't run anything behind the wall because it's solid Victorian - or if we decide we don't like it we've now wrecked the wall... or something? lolDefinitely will not go back to a "regular" thermostat.
All in all that seems reason enough to not get it, and of course I'm the idiot for wanting something more complicated than a "normal" thermostat. Argh, women.. /sexist
It is bizarre you can't mount it to the wall without old thermostat wires (very old school) or have to have a usb plug which I find strange for a permanent solution...