I think most things are covered. The main thing though is if you're buying a TDI I presume it's for long journeys? If so the DSG comes into its own. Motorway changes and quick drops to accelerate in D are just so much easier and yes lazy but it means you can relax. If you were retrofitting I presume a full MFSW would be needed. May be have a look over on mkvgti.co.uk. as I'm sure on them will have changed. I think Awesome GTI used to offer this as well...call N ask, they may at least say it possible and how...I know you couldn't use em as to far away mind.
And my opinion is I like both. I miss the connection when changing for corners, and my left foot still doesn't like the foot rest position.

If remapping the car the DSG can be a weak point in comparison to manual but DSG remaps are also available