I had a 2008 6MT since 2008 and just received my 2013 DCT comp pack M3 last week and all I can say is. WoW!!!
Ive always been a 6MT guy but was not ever really impressed or disappointed with the 6mt it was fine and that's it.
As far as the DCT... WOW!!! No regrets and I absolutely love it. I had never driven a DCT except for a short test drive that made me order my new one in DCT. I was afraid I may not like it but I absolutely LOVE it. This car feels completely different as a DCT. It's like a have a completely different type of car all thanks to this incredible tranny.
In my opinion this car is great as a 6MT but is much better with the DCT and I always drive it in manual mode it's just that amazing, fun an intoxicating!!!
2012 E92-M3 Space Grey on Fox Red, DCT
2011 B8 S4 S-Tronic , Black on magma red