I've had my RS for a good 9 months now as my only pin and it still manages to captivate me despite the amount I've played and the somewhat annoying linearity.
Although I've had it as my only pin for this long, I've only just got into the strategies involved in collecting souvenirs. I find that if I am half way across the country and my game is looking promising, I'll start collecting souvenirs. The more cities visited and the more bonus multipliers the bigger the bonus! I've had bonuses worth upwards of 1 billion and it's really satisfying watching the bonus count add up all of the souvenirs and then multiplying them!
Quick tip: Today I worked out how to get an absurd amount of points out of the Atlanta (Worker Trapped) mode. If the flying rocks is lit during the mode, go for this shot. Then launch the ball to the first hole (5x blast value) and if you can flip the ball from the lower flipper into the blast targets (not hole) then the mode value becomes 5x it's original value. The mode is then worth upwards of 150 million points!