Some of those products have the ability to modify some basic settings, but none will give you any true performance increases. For example, when I bought my 99 Trans Am the guy I bought it from had one of these programmers and gave it to me. I could remove the speed limiter, change the speedometer for different diameter tires, and some other basic stuff. I now have HP Tuners for full tuning ability, but you have to know what you are doing to use it.
Performance chips are garbage. If you don't want to spend the money for HP Tuners and the time to learn how to use it, look on the internet for someone selling pre-packaged tunes. You send your ECU to them, they re-program it, and send it back. Plug and play for you. Check forums specific to your truck to see what others have used.
2001 Bonneville SSEi (retired at 365,000 Kms.)
2014 Jeep Grand Cherokee Overland (yes, I know its not a GM)