Bully Dog B1540410

[09BlackBetty]

Hi, I have a 2009 Silverado with the 5.3L w/ 4spd auto, my question is have anyone tried the Bully Dog B1540410 Triple GT Gas power programmer. I want something that easy to take out(supposedly power programmers void factory 100,000mile warranty; is this true) and if you have the BD programmer does it really help with mileage and performance and drive ability of your truck(not really out for serious power) I'm currently at 18.5/19mpg city and 23-25 highway would love to squeeze a couple more mpgs out of it.

 

thanks, =)