Nope. No-one I know with a power valve has anything nice to say about them. No noticable improvement in performance but you can actually see the fuel guage going down quicker.
I agree - load of crap to be honest. Used to have one on an Orion I had once. Absolutely no difference to it what so ever - use the money for an induction kit if you've not already got one.
Along the same line of thinking how about the Ecotek valve? (www.ecotek.org.uk). I have actually never heard anything bad said about these, with better fuel economy being the biggest plus normally.
