I purchased the Superstar double chain device five weeks ago, and after a bit of messing about putting two bends in the backing plate to line it up on my Orange 5, I really cannot fault it. Not had any wet/muddy rides yet, so can’t comment in those conditions. Also, I have not noticed any extra noise from my drivetrain, which surprised me.
tom, I use it with my granny ring with no issues, so I’d suggest you go for one!