I prefer to bring along my own GPS from home - I've used it before, I am familiar with how it works. I've jumped in cars from Sapporo to Vilnius and found a GPS installed, but language and user-interface issues made those more of a puzzle. Language should be less of an issue in the UK, but familiarity counts - when you're disoriented and flummoxed, and behind the wheel in a foreign land (where they drive on the wrong side), it's no time to try and figure out how to work a new GPS system.
For me, I have all these working for me:
- GPS from home with updated database - check.
- Phone(s) and tablet(s), with map apps and connectivity plan - check.
- Paper maps, reviewed and folded for handy cross-reference for the day's drive - check.
- Head screwed on properly, brain engaged, aware of my location, destination and route, my surroundings and common sense switched on - check.
All four of these are good to have. Anything electronic can and will eventually fail you. Be ready when that happens.