FWIW: I worked with Ted and John Witte in their Tiptronic-Carrera. They went through the PDS and later AX'ed the car for a couple of seasons. John did very well with the car, and father Ted was right behind him.
From many laps in the right seat I observed that, although tempting, the manual mode is very challenging at an AX because the steering wheel turns over more than 180-degrees in some of the AX's tight turns, making it tough to "find the buttons" when tracking out. In some turns, the wheel does a 360-turn (corners with a 180-degree path and <50-foot radius) from turn-in to apex and back to track-out. It appeared to me that using the "auto" mode was much smoother and easier for performance driving at the AX level than trying to go "manual". Also, using the manual mode with the traction control off made it much easier to throttle-steer.
It is also my understanding that the computer systems that regulate the shifting points adjusts to driving styles. So that after a couple of laps, your computer registers "performance driving mode" and shifts at more aggressive rpm's (ask the Techie-types about this, as I'm no expert). If that's the case, your shifting is optimized by the car, and you can concentrate on driving the line, being smooth, looking ahead, and braking.
I could see the use for manual mode at the big tracks, where turning of the steering wheel rarely goes as far as AX's. At many of the bigger venue's manual mode might be better. But, since I've never driven a big track in a Tip, I'm only theorizing.
Just my thoughts and observations. Others will vary.
There was an article a few years back in Panorama about performance driving a Tiptronic, but alas, I don't know which issue, who the author was, or how to find it in Pano archives.
Hope that helps.
