The release bearing was playing up after 236k miles so I cant really complain.
According to the garage lads the only real problem was the release bearing itself.
The Dual mass was still in reasonable nick as was the rest.

So how does it go?
Well no real difference after 2 weeks and 1000 miles of taxiing with no particular change in smoothness
of the clutch action itself.
If the clutch ever goes again then its a much much cheaper job.
So worth doing
The transmission has noticeably less whining but I now can hear other noises !
Will monitor........if I can hear over the latest round of clacking antirollbar links....
Tony