Not a lot I can say about the various results people were achieving, but don't be so fast to blame the kits please.
As we tried hard to stress the kits were tested totally back to back to ensure accuracy. If you don't believe the results please phone Chris @ TOTD and ask him - he took the power runs: 01895 206777 - he would be more than happy to stand by the figures his RR provided. Both myself, James & Danny were surprised at the results the kit can achieve.
Output wise every car is different, we have worked on quite a number of 182s for instance; every one begins with a different initial output - post RS Works (inlets, airbox & remap) they all end up at about 180-183 if they are healthy & decatted. (All the before and afters are taken on the same RR, on the same day)
What this equates too is that some cars are more susceptible to tuning than others. Some gain over 12bhp to reach that figure, others as little as 5bhp at peak. As a bench mark I have never seen a car with that unit on it make more than 183bhp ATF if it is near standard - so if your car was already performing at 178bhp for instance I would only expect it make a few more BHP. In the example of our 182 it was a 160bhp as standard (which as you know is low) - the airbox & other modifications can raise it (and other cars to a common bench mark) - but not beyond. Maybe this needs to be reworded in the product description?
An induction setup will de-restrict a cars intake for improved charge density, but the mapping can also render that ineffective, Da your car was already providing 180ish BHP & it hasn't reacted to the airbox yes (although as already explained it is at the figure I would expect for a near standard car) but on the other hand I would (as James has pointed out) of expected it to be producing considerably more power than it is so something may need addressing - on the other hand every car is different - this may be the figures your car will produce in its current state of tune.
I hope that makes sense, any questions fire away.