Ive got a green panel filter. I posted some RR data on here about 10 days ago - I was moaning about the affect air temp has on performance because Id rrd in 91F!
Anyway, with standard filter got 163, and with green filter got 167. Someone pointed out that my original filter did have 9000 miles worth of crap in it, so just changing to a clean renault filter might have had a similar outcome.
On the positive side: i) definate increase in rortiness / noise which encourages you to use the whole rev range, just for that rally car sound, and ii) car appears to rev a little more freely after 6000 revs where previously Ive felt the power start to tail off.