Hi Michael,

The dual-mass flywheel is the original part so it's the one that is recommended, even if it is more susceptible to failure in the long run. There's not a huge difference in cost between them to get the work done now, though obviously you'd never expect to have to change the single-mass alternative again. 

The latter would cause more vibration at lower speeds especially, but it's difficult to know how obvious that would be until the work is done. 

With my own money, I'd go for the correct part.