Depends on the vehicle. My GF and I both have Golf GTDs. Mine manual, hers 6 speed DSG. I think it's the same box as the T6. Her old 15 plate Q3 TDI was 7 speed DSG - I cant say that felt any different to the Golf so same comments apply.
Manual is smoother and you're always ready for a corner because you have to change down in preparation, the DSG will always come out of a corner in too high a gear so it has to clunk down a couple of cogs and then catch up (you need clever GPS based gear selection which is coming on newer VWs). I always paddle it down a couple on the way into a corner and then a few seconds later it goes back to auto mode.
Manual is easier to do low speed manoeuvring as you can feather the gas/clutch - the Golf 6 speed DSG does nothing and then surges. Particularly tricky when trying to park right up against the garage door or reverse up a slope.
Manual is better for pulling out of a junction. When your foot is on the clutch the stop start will leave the engine running. The older generation DSGs were a nightmare for pulling away, the current one is quite consistent but you have to deactivate the stop start or drop into sport mode to keep the engine ready.
DSG is great in town (Milton Keynes) as you can set the active cruise control and drive right through without touching the pedals at all. Ultra lazy but very slick.
This doesn't apply in the Golfs but in a sports car the paddle change really helps when driving on a twisty road. My old Audi was quite scary having to grab a gear while accelerating out of a long bend. My newer S-Tronic version allows you keep the pedal down and flick another gear through. The Audi S Tronic is also quiet nice to manoeuvre. The Graziano box is very smooth at low speed.
As a country bumpkin camper van driver I wouldn't have DSG in the van as I'm often out on open roads or motorway. If I lived in town and it was a newer van with active cruise then DSG every time...
As clever as DSG is trying to get, it still cant hold a candle to a good old slushbox auto. New BMWs ... I've lost count on how many gears they have and you cant count them when you drive anyway Just too smooth... but I still wouldn't buy a BMW
