The chaps at Storm Developments have tested them all on the MK5 GTi, and found no significant gains, only losses from some. I'll stick with my Pipercross panel filter at Stage 2 based on their advice.
....In that case it doesn't say a lot for Storm Developments! Unless, of course, they tested all the intakes on a completely standard car
without either a turbo-back exhaust or remap, which isn't that likely as no gains would be expected in that example, so what would be the point?
With Turbo-back exhaust (Milltek), remap (Revo), I have dyno'd on Stock, with flat panel filter by ITG, with Carbonio scoop (that's all it is), and back-to-back with Forge Twintake <
ALL on JKM's Dyno-Dynamics rollers. My Mk5 K03 GTI is currently running 273 bhp on JKM's dyno.
For the OP, there may be some helpful information here:
http://www.mk5golfgti.co.uk/forum/index.php/topic,9988.0.htmlSo, providing that you have both a Turbo-back exhaust and a remap, I would recommend any of the Forge Twintake, ITG Maxogen, or Evoms, if you want good gains which are proven beyond doubt.