Just to add my experience (I drive Creepys old 335).
The DCT box has a separate sport button as opposed to moving the lever to the left on the conventional box to engage sport/sequential mode. This means you can have:
Drive with sport
Sequential/Manual with sport
Paddle changes with sport
This means that in the DCT box when the lever is moved to the left (sequential/Manual) it stays in the gear you have selected via the paddles and will hold it (I could sit and drive the car at 5,000 RPM in 3rd all day long). Which is unlike the conventional box that would change automatically after a few seconds or "normal" driving. This irritated me no end. That said, the DCT box won't allow you to go past the red line and does change up and down to protect the box.
In addition, when shifting down using the sequential box/paddles the box will blip the throttle for a more seamless change.
Oh, one final thing, on a long run you effectively have a heated gear knob due to the little LEDs in the lever itself