Go With Spectre
As far as I can tell, it does what it's meant to. I put this on before I put on my Spectre cold air intake to test it and noticed an immediate throttle difference, definitely added some power. And it hasn't messed with my mass air flow sensor. Don't buy this to save gas though, I haven't noticed much of a difference. Wasn't too hard to install either, just make sure you have a socket set and a pair of vice grips at least and you'll be fine.
Top Quality for Lower Price
I've had this installed for a couple weeks now, and as soon as I drove my truck afterwards I noticed a difference. Better throttle response, more power, my truck has really opened up now. As far as gas mileage I'm not sure, since I installed this with the Spectre Throttle Body Spacer as well, though it definitely didn't make it worse. Truck also shifts more smoothly, especially on the highway, gives the truck a nice growl. Installation took me maybe an hour, anyone can do it.