So I see there is a lot of discussion about the different transmissions. There are some points you always hear in favor of the DCT (and let's be honest here, the converter is the better option in many scenarios except very spirited driving or track use) and the main point is the faster shifting time.
If anyone is interested in some more or less factual evidence, I did some research and timed multiple videos of M4s and X3Ms to see their shift times. It actually took a bit of time to find videos for both cars where you could see the shifting time setting, the person was manually shifting at full throttle and see the padels and the rpm gauge at the same time.
For the X3M in the fastest transmission setting from the moment the shift pedal is pressed until the rpm gauge is fully in the next gear (i.e. when the needle is dropped down to ~4k rpm) it takes pretty much exactly 0.5s (14-16 frames in 30fps videos). You can time the shift time in the linked video above and I also used some videos uploaded by carwow (e.g.
this one).
The M4 Competition with DCT I used multiple videos from AutoTopNL and it indeed shifts quicker. From pedal press until the gear display changes it's 10 frames (60fps video), but the rpms didn't drop at that point at all. (I think at that point the next gear is engaged, but the clutch is not yet released). Until the rpms start to drop it takes another 10 frames and until the rpms fully drop to 4k rpm it takes yet another 20 frames. I do think there is some delay in the gauge (not digital) so in the best case scenario if you say the gear is engaged when the rpms start to drop its 20/60s = 0.33s and if you say the gear is engaged when the rpms hit 4k its 40/60s = 0.66s. The truth is probably somewhere in the middle.
I'm leaning more towards the first scenario, so the shifting times are ~0.33s for the DCT vs ~0.5s for the converter. Not that big of a difference as I expected. Of course there are other factors that play into it, e.g. the shifting characteristic/emotions (the little jerk from the clutch in the DCT).
Maybe some members that have a X3M or a M4 can make dedicated videos to let facts speak instead of emotions. Alternatively, maybe it is possible to log the shifting times.