I've just been watching a series of videos on the Images and Concepts and Brilliant Skiing DVDs and noticing the dramatic differences between their short turns and these "QCT"s.
Just guessing, because I've not seen the videos you refer to (link would help), I'd say the standout/defining difference would be "turn radius" which directly relates to the speed it takes to complete a turn, the deflection from a true fall line and the distance required to complete/finish the turn in order to gain the speed controlling advantages. How's my guess?
It occurs to me that there are more efficient ways to get to the outcome you are seeking than the movements you're making in these turns. Not that you have to change anything, of course, but just making sure that you see the implications of the stance and movements...
Stance, I'm assuming the amount of separation between the feet, this separataion can vary from turn to turn and can even vary and change during the same turn. It is often advantageous to initiate a turn with more separation and converge the feet/skis into the turn finish to focus energy build up. I don't suggest "locking" the feet together at any point of the turn, but generally when skiing natural terrain, closer is better than wider.
Exactly what movements are you referring to that could help TDK6 improve the roundness of his turn, the speed he can complete a turn in, and the subtle edge pressure timing required to cleanly link these turns? I'm sure these specific movement improvements could help a lot of other readers here also. Movements is a more difficult term to generalize as it can refer to anything from the desired degree of ankle roll at the turn initiation, the amount of retraction of the downhill ski at transition and everything in between that is needed to link turns as quickly and cleanly as TDK6's turns at the :24 sec mark in video 2. Are you serious that you can improve the speed and fluidity of these 5 turns by prescribing better/improved movements? If you can, supporting video demonstrating quicker,cleaner and rounder turns that utilize your improved movements/timing would be very enlightening and a high mark for skiers to emulate. Don't get me wrong here, I don't think TDK6's QCT's are the "best" I've ever seen, but those turns starting at the :24 sec mark are pretty damn clean and solid IMO.
I'm going to post a couple other QCT videos we've discussed in the past, including mine which are certainly not the "best" QCT's ever, but I'm not embarrassed to claim them mine either. I think what sets these QCT's apart from other short turn examples on the internet is the extremely tight radius, speed and roundness of the completed turn, all characteristic of turns needed to ski and hold the technical line.
Nice QCT's @ 1:00 mark.