I have plus six, with traction control. In sport mode, at 50mph, if I floor the throttle to overtake, I can feel the traction control kick in and smell rubber. I don't need more power!
Nobody does, but there is always a market for people who want to have the ultimate bragging rights down at the golf club. I'm sure that these things will sell well and none of them will ever be taken anywhere near their limits. With the improved suspension and drivetrain, hopefully we'll see fewer prangs like we seemed to get with the Plus Six.
Rather than more power, for both the Four and the Supersport, development needs to go into better door seals (acoustic and rain) and a laminated, noise insulating soft top, for sustained long distance touring, plus a quickly detachable wind protector behind the occupants, like Porsche / older Mercedes SLs. It shouldn't be too difficult to make a sensational improvement. Then they would have a true sports grand tourer (if you have a rear rack!).
Makes perfect sense to me.