Dr Pepper, I think I am what they call a 'troll'.
Ironic they go on about trolls really...
As for the induction kit debate, well I don't own/haven't tested a Cinq, so can be sure, but I do have some idea of the theory behind it.
Now I'm a little busy to go look it up, but off the top my head;
Cold air is more dense, therefore, you take in a larger mass of air (due to its reduced volume), which means you have a higher air/fuel ratio, so it is leaner.
This is where my memory is not 100% clear, but I seem to recall although less Torque is produced low down with a lean mixture, it is able to produce greater power (which of course is higher up in the rev range). I believe the charts I have seen for cars before and after a performance filter back this up, with any gains being shown high up the rev range.
There is also the issue of a higher quality filter having a lower pressure differential, meaning air can be drawn through more easily and hence why a car can often feel more responsive.
I realise this doesn't strictly answer the query, as this is not specific to a Cinq, but I hope it can held proved some of the reasoning used in chosing a performance filter.