I always think the same when out with my Porsche friends, the 997TurboS leaves me hanging on until I can stretch the 12C legs, mid range it then catches- but in fairness the numbers are all very similar when up in this spec of car.
Where the 12C amazed was through the wider twisty bends where it was inspirational and was crawling all over the back of the 911.
I posted a video and you can see how easy it was to close up or drop back.
I had one of the owners in with me and they felt that the 12C was slower and that it didn't give you that Turbo rush, this could be down to lack of lag or it just doesn't give the feel as much.
0-60 I find the 12C disappointing, however that's certainly not what I bought the car for.