OK, "kickdown" is a standard function of all automatic gearboxes (and pseudo-automatic, like CVT or DSG).
Underneath the throttle pedal, is a little 'button switch' - and when the throttle pedal is pressed HARD to the floor, it works this "kickdown" function. Some peeps never find kickdown - because they just never press the pedal hard enough!

Anyhows - let us say you are driving an auto - any auto, including a DSG. You are in full auto mode, trundling along at 35mph in a queue of traffic, stook behind a feckin caravan - you see a gap, and it is clear to overtake. The box will be in top gear - but - under normal circumstances, top gear and 35mph usually equals crap acceleration. But if you mash your foot to the floor - you can actually feel a little 'click' then this will activate the kickdown - at 35mph, kickdown will select the lowest possible gear instantly for maximum acceleration - probably go from 6th gear to 3rd. Now, providing the road is still clear - then not a prob - you will fly past the caravan, giving it the 'bird' as you pass, the transmission will change up through the gears as you reach the red line. Then when you are safely past, you ease back off the throttle to a more appropriate speed, and as you disengage the kickdown, the box will then relatively leisurley change up to 5th, then back into 6th.
Now, consider the exact same scenario - and with a normal auto. A moment after you floored the throttle and the box changed down - sommat tells you not to over take. The box is in third, the engine is reving its nuts off, you have taken your foot right off the gas, the fcukin box is still in 3rd - you are getting nagged at by SWMBO for thrashing the engine - then what seems like an eternity later, the box snicks into 4th and the revs drop a bit - another 45 minutes, it sneaks into 5th, and the engine quietnes down a little more - and after three light years - the box finally finds 6th again, and peace under the bonnet is restored. (OK, the timings are very slightly exagerated - but that is basically how it feels).
Do the same in a DSG - and it will IMMEDIATELY revert back to 6th (or whatever gear you were in before kickdown). Cool - no histrionics from mother in law in the back seat, no strange glares from other roadusers . . .

OK, for all those that don't like using kickdown, and prefer to 'paddle down' - well the kickdown does offer some significant advantages over the paddle down technique. The kickdown is instantaneous - and it can skip one, two or three intermediate gears - in extreme examples, going straight from 6th to 2nd. With the 'paddle down' - it ONLY works in a sequential manner - just like a motorbike gearbox. OK, if you only want to drop one cog, then it is even stevens between paddle down and kickdown - but if you want to drop three cogs, with paddle down, the box has to go from 6th to 5th . . . . then 5th to 4th . . . . then 4th to 3rd . . . and so on.
So all you 'non-believers' of DSG kickdown - go give it a try (including the "aborted overtake"). You'll be nicely surprised.
