I just installed the aFe Momentum GT intake, this made a big difference in throttle response.
I started with a K&N drop in filter but decided to go with an intake, night and day difference in response.
The only thing negative thing I noticed when I put on the intake was the acceleration was "rougher" (not talking about the noise), less refined is the best way I can describe it. It didn't bother me but I did notice this as well as my wife when she was driving it.
However I decided to add the aFe TB Spacer, this brought back the refinement to the acceleration. I can't say that I notice it made much of a difference in power, mostly top end seemed to pull more consistent but it did make it much smoother like stock but kept the added throttle response.
I really like the way the two work together, makes the truck much more enjoyable to drive and to get on the gas. Not only do I have the added power/throttle response but also the refinement is back.