Some points related to the C&D review
1) My gas pedal does not have a kickdown switch, and mine has never kicked down in manual mode. Only in D and S modes. I wonder if this is a feature of later models or if its 35is / American-spec models only.
EDIT: I stand corrected. My car indeed has a switch and it is activated very close to the "floor" or the gas pedal. In D mode it will kickdown even if I don't hit this switch, so I always thought it was just the carpet or something playing with my pedal. Anyway, if I hit this kickdown switch mine also kicks down in manual mode. I happens in all modes (DSC=off, Sport+ and Normal/Comfort). But if I activate the kickdown-switch and keep my pedal pressed to the floor it seems I can still upshift at low rpms in manual mode.
2) Manual mode with sport+ and with DSC=off is not the same thing. Shifting speeds are slower with DSC=off and you don't get launch control either. On the plus side, with DSC=off you can start to go sideways!
3) The actual DCT hardware is exactly the same with the 1-seres, 3-seres, Z4 and M3. Only the M5 and M6 comes with upgraded hardware AFAIK. So any differences arise from differences in the software and electronics (M drive logic vs dynamic driving control). I never had problems upshifting or downshifting during side-loading, but if it can't, it is because the software is protecting the hardware better than the software in the other cars. Same goes for the availability of faster shifting modes and red-line head-banging
4) So yes it manually upshifts at red-line. And of course it cant downshift if such an event would cause the engine to over-rev. Again, these are safety features. And btw when trying to achieve better lap-times, why go beyond 6500rpm? I am not sure why they keep reving this car all the way to the red-line during this track-review. Anyway, it is a bigger problem that mine sometimes double-upshifts in D and S modes if excessive wheel-spin occurs (in sport+). I have asked ESS if they would be interested in developing a solution taking into account all of the above, but the market seems to be too small to justify the development costs. On the positive side our DCTs should last longer due to the added safety.
5) Even if C&D claims that the DCT in the Z4 is less sporty than that in the 335is, it was still quicker around their track...
6) It looks like they were tracking with DSC=off, so if that 35is had adaptive suspension, they were indeed tracking it using the softest damper settings. They would have no other choice with DSC=off. Also their car looks like it had 19" with RFTs (which offers less grip than 18" with RFTs).
The most track-ready Z4 you can get is the Euro-spec 35i (because it has uprated brakes), 6MT, M-sport non-adaptive suspension (for best behavior with DSC=off), upgraded inter-cooler (and perhaps a very light ECU tune to keep things cool) and sporty non-RFTs probably on light 17" wheels.
But I don't want a track-ready Z4...