I think I have just been convinced that its worth paying the extra for the Tunit over the cheaper versions. I have experience of K&N's from previous motors and my bikes so I know they make a difference. Ultimately I want to get the absolute max MPG from my C-Max and also have the ability to blast it from time to time. I think like you I will use it as it comes and not bother with the set-up.
Your reply as indeed been very helpful and I would like to say thanks very much.
One more question, where did you get it from? was it direct from Tunit?
53 Plate Ford C-Max 2.0 TDCi Ghia