Got fed up of waiting for the OTA and sideloaded it today. I was having real issues with the drivers when trying to do it via Windows 7, so had a go using Ubuntu instead; job was done within 5-10 minutes. God bless Linux.
Just for good measure, I nabbed the GEL apk too and am now fully up and running with Kitkat. It seems to all work very nicely, although it's not quite as buttery smooth as my N5 in operation. Just the slightest judder going to the app drawer or swiping across to Google Now. I don't know whether that's an optimisation thing or hardware thing (probably a bit of both). Still, I'm happy; now for the impatient wait for 4.5 news