the Dual mass flywheels are a well known flaw on many of the new gen Diesels, and I have seen the odd post on here about DMF and DSG boxes.

Are the manuals prone to failing too?

I have found that by driving in harmony with the box, i.e. rev matching avoiding harsh engagement et c etc it is possible to extend the life of a DMF well past 100K miles, has this also been noted on the VRS?

(BTW I will be aiming to buy a car under 10,000 miles in the next few months)

Cars that suffer premature DMF failures have been repeatedly driven under load at low RPM.

If I try and accelerate when I'm in a high gear then I can feel some vibration from the DMF.

You are right, if you drive the car 'in harmony with the gearbox' you shouldn't experience any issues with the DMF.