Helix or Airaid

I am looking to buy a throttle body spacer for a 1997 vortec 5.7. I realize that the newer engines do not see near as much gain as the older cast iron ones do. However, I wonder if anyone has any opinions on which of these two spacers works better; the Helix or the Airaid?

myself I like helix. there is a change in the throttle responce.mpg gots a little better I think on my 96 5.7L I am running around 22 to 24 mpg

I have a 97 5.7 and i just went with the k&N fipk instead. its better than i thought, i got a noticible gain in power and the intake sound alone is worth it.. sounds like my buddy's 4 barrel opening up on his chevelle.. $250 free shipping is the best buy i found