Niki at R-Tech said no power reducing problems with the S2000 filters.... Main restriction on these cars is the Turbo Intake Pipe and the Down Pipe.
On all the cars I've owned where I've gone from using a paper based element to an oil based one I've had MAF issues within 10,000 miles.
And on any car where I've bought it with an oil based element already fitted there has been a MAF related problem along with it (including my current S3).
Been using S2000 filters for over 20,000 miles and not had a single error code relating to the MAF. For £13 a go there's no point buying any other type if you want a whooshing sound unless you're going for BIG power figures.
Considering a new MAF costs a minimum of £90 for a Bosch one I think it's a no brainer, rather than go and spend £££s on a fancy cone that goes through a new MAF every 10K miles.
Plus it takes seconds to fit!
I'd highly recommend my cowboy masking tape and Matt black paint suggestion.
Added a pic of mine.