My wife and I just signed up for our first RS tours, South England and Best of England. We are long time (pre Rick Steves) independent travelers but have used Rick's books as guidance on many of our trips and have watched all of his television shows. I also haunt these forums for advice. The only previous tours we have taken were to China and Myanmar where we just did not feel comfortable going it alone.
We were going to do an England trip on our own as what could be easier with a "common" language. Yes, I have driven on the left side of the road in Ireland. However, when I checked on car rentals I was told I was too old to rent a car. That was sort of a kick in the gut being told I was "old". Never felt that way. So now we will have a new experience having someone else do most of the planning. Just to keep the independent spirit going we are stopping in Iceland on the way over and then, when we get to England, stay in a castle for a couple of nights before joining the tours. After the tours we will stay on in London for 3 or 4 more days on our own.