Back when they were new, I rode a bike with the FFS briefly (not mine) and it was interesting to be able to shift while coasting, but I honestly thought it was dangerous to have the drivetrain spinning while coasting, because you could easily get something caught in there... especially while servicing the drive train of the bike.
I bought a bike once from a guy out in the country that swept up all the FFS equipped bikes he could find (especially Schwinn Suburbans as I recall) because he thought they were ideal for motorizing.
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Slow Ride Cyclists of NEPA
People do not seem to realize that their opinion of the world is also a confession of character.
- Ralph Waldo Emerson