Sorry, but it reinforces my argument that for real-world use, more than 6 gears is getting a bit silly/gimmicky/bragging-rights-ish...
7 driving ratios? If better performance were the "basic" goal, and "X" amount of R&D resources were available, wouldn't 30-40 lbft more torque be more enjoyable and useable than an extra gear stuffed in? Call me a caveman, but if Porsche came to me and said "we've got $150 million to spend, would you like a 7-speed PDK, or a far thriftier-to-bring-to-market 6-speed along with 30 more lbft of grunt?".... I wouldn't even stutter.
Yes, it's a "sports car", but it's a street car also... I'm guessing that they geared it so that it wouldn't be absolutely annoying to street drive, i.e. all of those ratios packed into your typical speed ranges, whereby you spend all day shifting and shifting with so little difference between gears. At least with a true manual, you can easily 1-3-5 shift, or 1-2-4-6, when you're just plinking around town or taking it easy... It's no sweat, you can drive your 6-speed like it's a 3-speed just by adjusting your pattern.
But with PDK, that set sequence is always in your way, isn't it?
It's just my guess, my attempt at slipping into the noggins of the engineers who put together this package.
I get the "optimal performance" mechanical-engineering argument for 7 driving-range gears completely. I get the race-car argument.
But hey, chalkboard math and real-world utility/interface don't always make a good marriage.
Besides, I'd sooner drive an airport van than have one of those techno-geek clutchless-manuals anyhoo...