[Steve Chryssos]

Well, we are co-mingling a few different issues here:

Sequential Transmissions: Good when shifted by a human, but hard to find one that will handle the abuse of direct, clutchless shifting when installed behind big power. They exist, but they are hard to apply to multi-use applications (drag race, road race and street use)

Mechatronic Transmissions: Doesn't matter if it is sequential or not--uses mechanical engineering, electrical engineering and software engineering to perform shifts. A more mainstream term would be robotics. Works great on an F1 car that operates within limited parameters (road race only) and is operated by a professional race driver (limited failsafes). When applied to the Aston Martin transmission shown above, the programming must account for novice drivers (driver error) and mundane tasks like parallel parking and other low speed maneuvering. Aston Marton does NOT want you to make 5th to 2nd downshifts. If you try, it either waits, or denies the innput altogether.
So the delay experienced by Jeremy Clarkson is due to "failsafe" programming that is designed for novice drivers. Warranty concerns supercede performance capability. And those sophisticated computers? They become downright stupid when faced with mundane tasks like parallel parking.
And as I stated above, the stock algorithm for a 2002 Aston Martin Vantage is most likely useless if applied to a twin turbo 69 Camaro (or Targetmaster 350 equipped 69 Camaro) As such, it would be virtually impossible to develop a production mechatronic solution for the hot rod aftermarket, since there is such a wide range of potential applications.

Are there exceptions? YES! And the exceptions are most likely the future of transmission technology.
1) I recently purchased an Audi A3 DSG. During low speed driving in auto mode, you would be hard pressed to tell the difference between the DSG and an old school automatic. In fact the salesguy kept calling it an automatic even though there are traditional gears inside the case. It's that good. Why? because it utilizes two clutches. And in manual mode--during performance driving, it shifts just like Michael Shumachers F1 car--with lightning quick shifts (where applicable) and no rpm drop between shifts. It's said that DSG will obsolete CVT almost immediately and single clutch mechatronic manuals (on street cars) shortly thereafter.
2) Manumatics. The Mercedez 7G has a stout looking lock-up clutch in the torque converter. So, when locked up and in manual mode (even in 1st gear), you'd have a hard time telling it apart from a true "direct drive" manual. And torque converters are more forgiving that true clutch assemblies. I'm dying to try out a new 6L80E.

The line has become very blurry indeed.
/Steevo