I have a Flight Deck also and it has served my purposes well. Like you said, it is simulated cadence calculated from the gear ratio and the speed, so you can be coasting and still get a cadence reading. It doesn't know if you are pedalling or not. You really have to make sure that all of the information such as the number of gear teeth and wheel diameter is correct to get an accurate reading. What I really like about it is you can look to see what chainring-cog combination you are riding in without looking back under you right arm. What I don't like about it is that it is kinda easy to accidentally reset your mileage and elapsed time with the placement of the buttons in the brifter hoods, but it also allows you to change from one function to another more easily. It is a little succeptable to RFI.....I don't think that my max speed on a flat last June was really 130 MPH!