I haven't been on the forum for a while; too busy out riding my RT-S. However, I saw the ECO thread and thought that since that is the only mode I use, I better weigh in. When I first started using it, I was slightly distracted by watching the screen. However, that didn't last long, because I learned to anticipate shift points based on feeling/hearing the RPM. Sometimes I glance down when shifting into 5th and 6th gears to know the exact moment when I can shift into those gears (32 mph going into 5th gear, and 38 mph going into 6th gear). Unlike others have mentioned, ECO does have a payoff. I get well above 40 mpg on every tank. Some of the other savings that is also often overlooked is longer tire wear and less wear and tear on the motor.
I've ridden motorcycles for almost 30 years, but since owning the new RT-S, I've given them up. I just enjoy the RT-S way too much to justify keeping the bikes that I had (BMW K1600GTL & Triumph Tiger Explorer). Getting 42-45 mpg on my RT-S is icing on the cake. If I wanted to drive fast, I would have bought a Hayabusa.