People in both places were pretty friendly with London's folks being friendlier. One thing about it, both places were a heck of a lot safer than the United States. You wouldn't show up in New York City or any other large city and go just about anywhere you wanted. These two European cities were far and away safer than being here in the U.S.A. We were in London during the Cricket finals and also during Wimbledon matches so things were a bit crowded on the subway. Learned quite a bit about London that I didn't know.
Speed is in miles per hour and distance is in miles with yards as a sub-measure.
I think they use liters so that you don't realize just how expensive the gasoline can be. Of course they do drive on the opposite side of the street which can be disconcerting if you're new to driving there. You should give it a try when you go there. It's supposed to be the oldest inn in England dating back to the 900s. We highly recommend British Airways for the airline and got lots of deals by using them as our airline.