I own a 135i 7DCT as well as an F30 335i 8AT and an Audi A3 6DSG. Considering I'm an actual track whore and not a magazine racer I will tell you that the 8AT is indeed smooth and downshifts quickly into the meat of the powerband where the 7DCT hesitates a bit before dumping down...but the 8AT technically loses out to both Dual Clutch Gearboxes in pure upshift speed. On the track the DCT is quite the thing when shifting manually and the 8AT feels a little less immediate but in real world driving applications it is almost negligible and the 8AT's 300ms shift speed is unbelievably fast for a torque converted tranny while the 200ms-60ms range of the getrag DCT unit is technically faster but not quite as smooth at speed. Ultimately it's quite inconsequential and I think ZF has done an amazing job with the unit and bmw, as well, with their programming of it. There's a reason there are several car manufacturers using it now.
NOTE: a post above notes that the DCT cannot disengage to skip downshifts...this is entirely untrue. It can go from 7-4 in a jiffy without needing to go down each gear.
M235i F22: Prem.Tech.+
335 F30 MSport: Prem.Tech.NAV.+
X-335 E92: Prem.Sport.+
Audi A3: FBO.
Last edited by TreDirtyFive; 11-23-2012 at 05:18 AM.